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Graphical abstract Highlights • σ-Hole tetrel bonding interactions: A CSD survey of tin and lead compounds. • Intra and intermolecular tetrel bonding interactions in tetravalent Sn(IV) and Pb compounds. • Tetrel bonding interactions in Pb(II) hemidirectional coordination compounds. Abstract A tetrel bond can be defined as an interaction between any electron donating moiety and a group 14 element acting as Lewis acid. Experimental and theoretical research on this interaction has rapidly grown in recent years. A reason for that is related to the fact that it can be easily exploited to design supramolecular structures. This review is devoted to highlight the role of heavier tetrel atoms (tin and lead) as promising building blocks for the construction of supramolecular assemblies and supramolecular MOFs based on tetrel bonding interactions. In the case of tin, the number of investigations on this topic is limited, therefore we also provide a survey of crystal structures retrieved from the Cambridge Structural Database where this interaction is crucial for the crystal packing stability. We have sub-divided this part taking into consideration the atom or group of atoms acting as lone pair donor atom (O, S, N, halogen) and also the intra- or intermolecular nature of the interaction. This survey evidences that close contacts between Sn and lone-pair-possessing atoms are quite common and oriented along the extension of the covalent bond formed by the Sn and the most electron-withdrawing substituent. Moreover, it provides experimental evidence of the ability to act as electrophilic site (tetrel bond donor). This ability has a prominent role upon the conformations and the packing of Tin organic derivatives in the solid state. For Pb(IV) organic compounds, where the geometry around the metal center is tetrahedral we also provide a survey of crystal structures retrieved from the Cambridge Structural Database. To our knowledge, this type of analysis in Pb(IV) is unprecedented in the literature. For Pb(II), we have selected several works where the tetrel bonding interaction is used as a robust tool in crystal engineering and supramolecular chemistry. [ABSTRACT FROM AUTHOR]

Five new Pb(ii) complexes of hydrazone-based and Schiff-based ligands and three different anionic co-ligands (azide, thiocyanate and bromide) have been synthesized and characterized by structural, analytical and spectroscopic methods. This variety of ligands can coordinate to the Pb(ii) metal center in a tridentate or tetradentate fashion via a different combination of any of nitrogen, oxygen and sulphur donor atoms. Moreover, the organic ligands can be in mono-deprotonated or neutral forms. By using single-crystal X-ray crystallography, we show that the synthesized complexes aggregate into larger supramolecular entities due to the formation of noncovalent tetrel bonding interactions. The Pb(ii) center is hemidirectionally coordinated even in those complexes where the coordination number is six. Consequently, this is sterically ideal for establishing tetrel bonding interactions with electron-rich nitrogen, bromide or sulphur atoms. These contacts are significantly larger than the sums of the covalent radii. Hence, they can be described as non-covalent tetrel bonding interactions. They interconnect the covalently bonded units into supramolecular assemblies (dimers or tetramers). The contribution of contacts involving the Pb atom has been studied using Hirshfeld surface analysis and fingerprint plots. We have analysed the supramolecular assemblies observed in the solid state by means of DFT calculations and characterized them using Bader's theory of atoms-in-molecules. [ABSTRACT FROM AUTHOR]

Crystal structures of aminopyridine–succinate salts (1–3) were solved by single crystal X-ray diffraction where salt bridge (SB) interactions between the succinate and protonated aminopyridine dominated their supramolecular architecture. X-ray crystallography reveals that compounds 1 (hydrogensuccinate 2-amino-5-methylpyridinium salt) and 2 (hydrogensuccinate 2-amino-4-methylpyridinium salt) exhibit C–H…SB…π+ assemblies, while compound 3 (succinato-aminopyridinium salt) displays unique N–H…SB…lone pair (l)p networks in the solid state. These unexplored extended networks are described and investigated for the first time in crystalline structures. Our study also describes the duality of the salt bridge in establishing π-facial interactions with electron rich and/or electron poor moieties depending on the positive or negative nature of the SB counterpart that interacts with the SB surface. The theoretical study combines an energetic investigation of the noncovalent forces that contribute to the extended supramolecular network and the characterization of the diverse interactions by means of Bader's theory of “atoms in molecules” (AIM) and the NCIplot index. [ABSTRACT FROM AUTHOR]

Four new Pb(ii) complexes of nicotinoylhydrazone and picolinoylhydrazone-based ligands and three different anionic co-ligands (acetate, thiocyanate and iodide) have been synthesized and characterized by structural, analytical and spectroscopic methods. The ligands coordinate to the Pb(ii) metal center in a tridentate fashion via two nitrogen and one oxygen donor atoms either in mono-deprotonated or in neutral forms. Single-crystal X-ray crystallography reveals that the molecular complexes aggregate into larger entities depending upon the anion coordinated to the metal centre. The Pb(ii) center is hemidirectionally coordinated and, consequently, it is sterically ideal for establishing tetrel bonding interactions. Consequently, in the crystal structures of all the complexes, the Pb participates in short contacts with nitrogen, iodide or sulphur atoms. These contacts are shorter than the sums of the van der Waals radii and larger than the sums of the covalent radii, therefore they can be defined as non-covalent tetrel bonding interactions. They interconnect the covalently bonded units (monomers or dimers) into supramolecular assemblies (1D infinite chains and 3D structures). Hirshfeld surface analysis and fingerprint plots have been used to analyse the contribution of contacts involving the Pb atom. We have analysed the interesting supramolecular assemblies observed in the solid state of all four complexes by means of DFT calculations and characterized them using Bader's theory of atoms-in-molecules. [ABSTRACT FROM AUTHOR]

A new mononuclear tetra­hedral CoII complex, di­chlorido­bis­(imidazo[1,2-a]pyridine-κN1)cobalt(II), [CoCl2(C7H6N2)2], has been synthesized using a bioactive imidazo­pyridine ligand. X-ray crystallography reveals that the solid-state structure of the title complex exhibits both C—H⋯Cl and π–π stacking inter­actions in building supra­molecular assemblies. Indeed, the mol­ecules are linked by C—H⋯Cl inter­actions into a two-dimensional framework, with finite zero-dimensional dimeric units as building blocks, whereas π–π stacking plays a crucial role in building a supra­molecular layered network. An exhaustive investigation of the diverse inter­molecular inter­actions via Hirshfeld surface analysis enables contributions to the crystal packing of the title complex to be qu­anti­fied. The fingerprint plots associated with the Hirshfeld surface clearly display each significant inter­action involved in the structure, by qu­anti­fying them in an effective visual manner. [ABSTRACT FROM AUTHOR]

Using ab initio calculations, we analyze the interplay between π‐hole interactions involving the nitro group of 1,4‐dinitrobenzene and lone pair···π (lp···π), C–H···π or metal(M)···π noncovalent interactions. Moreover, we have also used 1,4‐phenylenebis(phosphine dioxide) for comparison purposes. Interesting cooperativity effects are found when π‐hole (F···N,P) and lp···π/C–H···π/M···π interactions coexist in the same supramolecular assembly. These effects are studied theoretically in terms of energetic and geometric features of the complexes, which are computed by ab initio methods (RI‐MP2/def2‐TZVP). A charge density analysis using the Bader's theory of “atoms in molecules” is carried out to characterize the interactions and to analyze their strengthening or weakening depending on the variation of charge density at critical points. The importance of electrostatic effects on the mutual influence of the interaction is studied by means of molecular electrostatic potential calculations. By taking advantage of these computational tools, the present study examines interplay of these interactions. © 2017 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Two new Co(II) and Cu(II) coordination polymers, {Co(HL1)2(μ-L2)(H2O)2}n (1) and {[Cu(HL1)2(μ-L2)H2O]·H2O}n (2) (H2L1 = Phthalic acid and L2 = 2-aminopyrazine), have been synthesized by slow evaporation of solvent and characterized by IR spectroscopic, elemental, single-crystal X-ray diffraction and thermal analysis. X-ray results indicate that in both the polymers, phthalate acts as a monodentate ligand and the aminopyrazine ligand is responsible for the formation of the infinite one-dimensional chain structure. The solid-state structures are stabilized through hydrogen bonds and N-H···π interactions by generating two-dimensional layered structures. Finally, the non-covalent interactions have been studied energetically and using Bader's theory of atoms in molecules by means of Density Functional Theory (DFT) calculations. The influence of the metal coordination on the strength of the interaction has been studied using molecular electrostatic potential surface calculations. [ABSTRACT FROM AUTHOR]

• Four triazole derivatives were synthesized and characterized by the structural investigation. • Detail structural analysis provides an understanding of the effect of various substituent on the supramolecular construct. • The nature and energetics of the intermolecular interactions involved in 3D networks have been discussed and presented via inputs from different computational approaches. • Along with strong H-bonds, weak intermolecular interactions also contribute comprehensively towards the overall stability of these crystal structures. This manuscript comprehensively examines four triazole derivatives using Hirshfeld surface and fingerprint analysis, PIXEL energy for molecular pairs, lattice energies for crystal packing, atoms-in-molecules (AIM) topological analysis, and noncovalent interaction (NCI) plots for intermolecular interactions. The fingerprint plots of the Hirshfeld surface analysis provide a quantitative picture of various substituent effects on the noncovalent interactions that contribute to the crystal packing stabilization of these four structures (TN1 – TN4). The PIXEL method provides the intermolecular interaction energies for the molecular dimers observed in these structures. The nature and strength of intermolecular interactions at the (3, -1) bond critical point have been studied using the approach of atoms-in-molecules (AIM) via a topological analysis of the electron density distribution. The topology parameters suggested that the intermolecular interactions are classified as closed-shell interactions, and NCI plots were employed to identify the nature of the involved noncovalent interactions. Therefore, a detailed computational analysis renders insights into the electronic characteristics of different noncovalent interactions in the solid state of the structures in the current investigation. [ABSTRACT FROM AUTHOR]

The annelated imidazolium salt 1-methyl-2-(pyridin-2-yl)imidazo[1,5- a ]pyridin-4-ylium hexaflurophosphate ( 1 ·HPF 6 ) has been synthesized by via formylative cyclization of the corresponding Schiff base 2-acetylpyridyl- N -(2-pyridyl)methylamine using standard conditions followed by anion metathesis with NH 4 PF 6 . Reaction of 1 ·HPF 6 with silver oxide and palladium chloride led to the formation of the palladium complex [Pd( 1 ) 2 Cl]PF 6 , 2 . Subsequent reaction of 2 with AgPF 6 gave the palladium complex [Pd( 1 ) 2 ][PF 6 ] 2 , 3 . The complexes have been fully characterized by different spectroscopic techniques and finally the solid state structures of 2 and 3 have been determined by single crystal X-ray diffraction studies. The catalytic activities of 2 and 3 have been tested in the Suzuki–Miyaura coupling reactions of several activated para -functionalized aryl bromides with phenyl boronic acid to find that 2 is slightly more efficient than 3 . [ABSTRACT FROM AUTHOR]

Three new manganese(II) complexes, namely [Mn(NCS) 2 (L) 2 (CH 3 OH) 2 ]·2CH 3 OH ( 1 ), [Mn(NCS) 2 (L) 2 (C 2 H 5 OH) 2 ]·2C 2 H 5 OH ( 2 ) and [Mn(NCS) 2 (μ-L) 2 ] n ( 3 ) (L = 4-acetylpyridine nicotinoylhydrazone) have been synthesized and characterized by elemental analysis, IR spectra, single-crystal and powder X-ray diffraction analysis. In order to investigate the effect of solvent, methanol, ethanol and acetonitrile have been used in the synthesis of complexes 1 – 3 , respectively. When using methanol as solvent, complex 1 was obtained. Complex 2 was synthesized under the similar synthetic conditions of complex 1 using ethanol instead of methanol as a solvent. To further examine the effect of solvent on the structure, we used CH 3 CN as a solvent instead of the ethanol. Unlike the complexes 1 and 2 , complex 3 was formed with 1D chain structure. The energetic features of the noncovalent interactions observed in the solid state of compounds 1 and 2 have been studied by means of DFT calculations. [ABSTRACT FROM AUTHOR]

The crystallography of mono-p-substituted derivatives of 1-(arylamino)-1,2,3-triazole-4-carbohydrazides, 1 (X = H), 2 (F), 3 (Cl) and 4 (Br), and a 2,5-dichloro (5) analogue, shows the molecular structures to be similar. Distinct hydrogen bonding patterns based on N–H…N and N–H…O are observed in their crystal structures with 1, having two independent molecules comprising the asymmetric unit, displaying one pattern, 2 and 5 another, and 3 and 4 yet another. Geometry optimisation calculations indicate that any conformational differences in the solid state do not persist in the gas-phase and that no influence of the substituents is seen on the geometric parameters. A natural population analysis, for both experimental and optimised structures, shows that the charge on the triazole-N3 atom is at a maximum for 1, as opposed to 2–5, an observation correlated with its distinctive packing based around a supramolecular synthon not seen in the other structures. For the molecules having electronegative substituents, molecular electrostatic potentials show that the energies of the amine-H4n atoms are reduced for 2 and 5, compared to 3 and 4. A further distinction in 2–5 is indicated by the Hirshfeld surface analysis which highlights the importance of π…π interactions in 2 and 5, i.e. with the more electronegative substituents. Clearly, there is interplay between various factors but all correlated with the influence of the electronegativity of the substituent(s). [ABSTRACT FROM AUTHOR]

Thenovel noncovalent interactions between the charged and neutralaromatic rings and with anions are utilized to design the solid-stateassembly of triply protonated PTPH3(PTP = 4'-(4-pyridyl)-3,2':6',3"-terpyridine)with H2O and three ClO4-,which is synthesized and characterized by single-crystal X-ray diffractionanalysis. Crystallography reveals that the π+-π+, π+-π, and various anion···πinteractions are the major driving forces in the stabilization of the self-assembled structure. In the title complex, a layered assemblyis formed through the mutual influence of π+-π+and π+-π interactions. Theanions are interacting with the charged π-acceptors, which areagain stabilized through π+-π interactions. Therefore, the overall stabilization is governed through π+-π/π-π+, (π+-π+)n, and anion···π+/π+-π/π-π+networks in thesolid state. The interaction energies of the main driving forces observedin the crystal structure have been calculated using density functionaltheory. In addition, the short O···O contact betweenClO4-anions has been analyzed in detailboth computationally and exploring the Cambridge Structural Database. [ABSTRACT FROM AUTHOR]

Highlights: [•] Supramolecular self-assembly. [•] Layer and bi-layer architecture. [•] Cooperativity of noncovalent interactions. [•] Quantification of intermolecular interactions. [•] Hirshfeld surface and fingerprint plot. [ABSTRACT FROM AUTHOR]

Highlights: [•] Structural elucidation from X-ray data. [•] Molecular structure of ortho-hydroxy acetophenone. [•] Intermolecular interactions. [•] Hirshfeld surface analysis. [ABSTRACT FROM AUTHOR]

Abstract: A unique discrete octameric cluster of lattice water molecules in the lattice voids produces a 3D supramolecular architecture through hydrogen bonding interactions. These cubic water clusters have not been structurally documented so far and illustrate new modes of supramolecular association of water molecules. [Copyright &y& Elsevier]

Highlights: [•] Annulated NHC ligands. [•] Pd(II)–NHC complexes. [•] Steric crowding of α-CH3. [•] Pd(II)–NHC catalyzed Suzuki coupling reaction. [ABSTRACT FROM AUTHOR]

The solid-state complex [PTPH3](NO3)3·2(HNO3) (1) has been synthesized and characterized by X-ray studies, where PTPH3 is the triply protonated form of 4′-(4-pyridyl)-2,2′:6′,2′′-terpyridine (PTP). The solid-state structure of the complex reveals that the π+–π+ interactions are the major driving force in the crystal packing while π+–π, π–π and π–anion interactions assist the overall stabilization of self-assembly. Complex 1 exhibits two different π-stack layers, where layer 1 is generated through π+–π+ interactions and the mutual forces of π+–π+ and π+–π form layer 2. The interaction energies of the main driving forces (π+–π+, π+–π and π–anion interactions) observed in the crystal structure have been calculated using dispersion-corrected density functional theory (DFT-D). An analysis of the Hirshfeld surface of complex 1 shows the intermolecular interactions involved within the crystal structure and corresponding quantitative information are presented by fingerprint plots. [ABSTRACT FROM AUTHOR]

Nonlinear optical material l-valine hydrochloride monohydrate (VHM) was synthesized and single crystals were grown by slow evaporation of its aqueous solution at a constant temperature (42 °C). The crystal structure of VHM was redetermined by single crystal X-ray diffraction analysis. The physicochemical properties of the grown crystal were characterized by thermal and optical analysis and a measurement of hardness. The second harmonic generation efficiency of VHM was investigated by a powder method and it was found to be 0.3 times that of potassium dihydrogen phosphate (KDP). [ABSTRACT FROM AUTHOR]

Highlights: [•] Cocrystals having 2D layer architecture. [•] Cooperativity of strong hydrogen bonding and weak π–π stacking interactions. [•] Quantification of intermolecular interactions. [•] Hirshfeld surface and fingerprint plots. [ABSTRACT FROM AUTHOR]

A MgII complex containing malonate as the primary ligand and 4-aminopyridine as the secondary ligand (counter ion), namely (ampyH)2[Mg(mal)2(H2O)2] ( 1; ampyH = protonated 4-aminopyridine, malH2 = malonic acid), has been synthesized from purely aqueous media just by mixing the reactants in their stoichiometric proportions. Its crystal structure was determined by single-crystal X-ray diffraction. In 1, monomeric metal malonate units [Mg(mal)2(H2O)2]2- are interlinked through hydrogen bonds to generate infinite 2D supramolecular sheets. These supramolecular sheets are bridged by 4-aminopyridine molecules to generate a 3D structure. Similar complexes containing 4-aminopyridine as the secondary ligand (counter ion) show an identical self-assembly process, except for the copper analogue, which was found to be polymeric in nature. By means of DFT theoretical calculations (BP86-D3/def2-TZVPD), we provide a plausible explanation for this different behaviour and present an energetic analysis of the complexes. The Hirshfeld surfaces of the Mg structure and related Cu, Ni and Co structures were analyzed to clarify the nature of the intermolecular interactions. [ABSTRACT FROM AUTHOR]

Highlights: [•] NCN pincer NHC ligand. [•] Ag2 cluster stabilized by NHC. [•] d10–d10 ‘argentophilic’ interaction and luminescence. [ABSTRACT FROM AUTHOR]

Abstract: An anthrilidine derivative of arjunolic acid, namely, anthrylidene methyl arjunolate (1) have been synthesized and characterized by X-ray structural studies with a detailed analysis of Hirshfeld surfaces and fingerprint plots facilitating a comparison of intermolecular interactions in building self-assembled framework. The central six member fused ring, which is flattened due to the presence of a Cbond, adopts a sofa conformation, whereas other fused six member rings assumes chair conformations. All the fused rings have trans fusion except one ring junction, which is in cis fusion. The crystal packing of (1) exhibits intermolecular OO and CO hydrogen bonds forming (7) ring motif and are further linked through Cπ (arene) bonds to generate a framework. The fingerprint plots enabled to decode intermolecular interaction types present in the title crystal structure and the structures retrieved from the Cambridge Structural Database (CSD). A comparison of Hirshfeld surface in the title compound with similar structure retrieved from the CSD has been presented. [Copyright &y& Elsevier]

Three Co(II)-malonate complexes, namely, (C5H7N1)4[Co(C3H1O4)2(H2O)2](NO3)2 (1), (C5H7N2)4[Co(C3H2O4)1(H2O)2](O4)2 (2), and (C5H7N2)4[Co(C3H2O4)2(H2O)1](PF6)1 (3) [C5H,N1 = protonated 2-aminopyridine, C3H4O4 = malonic acid, NO3 = nitrate CIO4 = perchiorate, PF = hexafluorophosphate], have been synthesized from puxely aqueous media, and their crystal structures have been determined by single crystal X-ray diffi-action. A thorough analysis of Hirshfeld surfaces and fingerprint plots facilitates a comparison of intermolecular interactions in 1-3, which are cnacial in building supramolecular architectures. When these complexes are structurally compared with their previously reported analogous Ni(II) or Mg(II) compounds, a very interesting feature regarding the role of counteranions has emerged. This phenomenon can be best described as anion-induced formation of extended supramolecular networks of the type lone pair-л/л-л/,л-anion-л/л-lone pair and lone pair-л/л-л/л-anion involving various weak fortes like lone pafr-л л-л, and anion-л interaction. The strength of these at contacts has been estimated using DFF calculations (M06/6-31+G*), and the formation energy of the supramolecular networks has been also evaluated. The influence of the anion (NO3, CIO4-, and PF6-) on the total interaction energy of the assembly is also studied. [ABSTRACT FROM AUTHOR]

Abstract: A benzylidene derivative of arjunolic acid, namely, para-nitro benzylidene methyl arjunolate (3) have been synthesized and characterized by X-ray structural studies and the electronic structure was calculated at the DFT level with a detailed analysis of Hirshfeld surface and fingerprint plot facilitating a comparison of intermolecular interactions. The crystal packing of (3) exhibits intermolecular O–H⋯O and C–H⋯O hydrogen bonds forming linear chains propagating parallel to [100] and [010] directions, respectively, which are further linked through C–H⋯π (arene) bonds to generate two-dimensional framework. Investigation of intermolecular interactions and crystal packing via Hirshfeld surface analysis reveals that more than two-thirds of the close contacts are associated with weak interactions. Hirshfeld surface analysis for visually analyzing intermolecular interactions in crystal structures employing molecular surface contours and 2D fingerprint plots have been used to examine molecular shapes. The large HOMO–LUMO energy gap indicates a high kinetic stability for the title compound (3). [Copyright &y& Elsevier]

Two chromone derivatives C11H10O3(1) and C11H10O2(2) have been synthesized and characterized by X-ray structural studies with a detailed analysis of the Hirshfeld surfaces and fingerprint plots facilitating a comparison of intermolecular interactions in building different supramolecular architectures. The title compounds are associated through π–stacking interactions and the linear stacking of π–π forces can be thought as the influencing agent for the organization of the title compounds into hydrogen bonded supramolecular layers and are responsible as well for the strengthening of the molecular assembly. Investigation of the intermolecular interactions and crystal packing viaHirshfeld surface analysis reveals that more than two-thirds of the close contacts are associated with weak interactions. The fingerprint plots demonstrate that these weak interactions are important for both local and crystal packing. A comparison of the Hirshfeld surface in the compounds with similar substituted chromone derivatives in the Cambridge Structural Database (CSD) has been presented. [ABSTRACT FROM AUTHOR]

Abstract: A dinuclear FeIII complex [{Fe(TPA)Cl}2O](ClO4)2·H2O (1) where TPA is tris(2-pyridylmethyl)amine, has been synthesized and characterized by X-ray structural studies with a detailed analysis of Hirshfeld surfaces and fingerprint plots facilitating a comparison of intermolecular interactions in building different supramolecular architectures. Molecules of (1) are linked by self-complementary hydrogen bonds into two-dimensional framework, whose formation is readily analyzed in terms of substructures of lower dimensionality with finite zero dimensional dimeric units as the building blocks within the structure. The crystal packing is also stabilized by C–H⋯π and π–π stacking interactions and is responsible for the formation and strengthening of three dimensional supramolecular assembly. Investigation of intermolecular interactions and crystal packing via Hirshfeld surface analysis reveals that more than two-thirds of the close contacts are associated with weak interactions. The fingerprint plots demonstrate that these weak interactions are important for both local and crystal packing. A comparison of Hirshfeld surface in the complex with similar structure retrieved from the Cambridge Structural Database (CSD) has been presented. [Copyright &y& Elsevier]

Abstract: The crystal structures of two pyrazole derivatives, C5H10N4O2 (1), which is a neutral species and C8H12N6O3S (2), a nitrate salt, have been determined from single crystal X-ray analysis and their electronic structures were calculated at the DFT level with a detailed analysis of Hirshfeld surfaces and fingerprint plots facilitating a comparison of intermolecular interactions in building different supramolecular architectures. Investigation of intermolecular interactions and crystal packing via Hirshfeld surface analysis reveals that the close contacts are associated with weak interactions and the fingerprint plots demonstrate these weak interactions. The large HOMO–LUMO energy gap indicates a high kinetic stability of both the compounds in their electron transfer. [Copyright &y& Elsevier]

Abstract: A mononuclear CuII complex [Cu(IDA)(2,2′-dypam)(H2O)]·H2O (1) where H2IDA and 2,2′-dypam are iminodiacetic acid and 2,2´-dipyridylamine, respectively, has been synthesized and characterized by X-ray single crystal structure analysis. The Cu(II) atom exhibits an unsymmetrical elongated octahedral coordination type 4+1+1. X-ray crystallography reveals that complex (1) has an unprecedented fac-O2 +N(apical) IDA conformation, in the trans-site of Cu–N (IDA-like) bond, in contrast with structural co-relations for complexes with Cu/(IDA or IDA-like)/N-heterocyclic donor ratio 1/1/2 and closely related compounds fac-NO+O(apical) IDA-like conformation and one N-heterocyclic donor in the trans-site to the Cu–N (IDA-like) bond. These findings are attributed to the influence of π–π stacking, C–H⋯π interactions in the molecular recognition process. Moreover, the aromatic moieties of 2,2′-dypam are engaged in carbonyl⋯π interaction with the non-coordinated carbonyl groups of IDA ligand and giving rise to a remarkable supramolecular carbonyl–π/π–π/π–carbonyl interactions. [Copyright &y& Elsevier]

Abstract: A new nonlinear optical material L-valine L-valinium hydrochloride (VHCl) has been synthesized and identified by CHN test, FT-IR spectroscopy and XRD analysis. Formation of new crystal has been confirmed by single crystal X-ray diffraction analysis. VHCl crystallizes in monoclinic system with cell parameters a=11.144(2)Å, b=5.179(9)Å, c=13.028(2)Å, β=111.85(3)°. Thermal stability of the crystal was investigated using thermogravimetric and differential thermal analysis studies. The suitability of this material for NLO application was studied by optical transmission studies and second harmonic generation (SHG) efficiency measurement by powder method. SHG efficiency of VHCl is found to be comparable to KDP. The molecular geometries and electronic structure of VHCl were calculated at the DFT level using the hybrid exchange-correlation functional, BLYP, PW91, PBE and BP. [Copyright &y& Elsevier]

Abstract: Crystal and molecular structure of a labdane diterpenoid glucoside, andrographiside (1) is determined from 2D-NMR and X-ray diffraction data. The 2D-NMR study indicates that the carbohydrate moiety is in β-linkage and the sugar moiety is linked to C-19 of the aglycon. These observations are further confirmed from the X-ray diffraction studies. Both the six-membered rings are in chair conformation whereas the glucose ring adopts a twist-boat conformation. The molecular geometries and electronic structure of (1) were calculated at the DFT level using the hybrid exchange–correlation functional, BLYP, PW91 and PBE. [Copyright &y& Elsevier]

Abstract: Two ortho-hydroxy acetophenones, namely 2,6-dihydroxy-4-methyl acetophenone [C9H10O3] (1) and 2,4-dihydroxy-3-acetyl-6-methyl acetophenone [C11H12O4] (2) have been synthesized and characterized by spectroscopic and X-ray structural studies. Compound (1) crystallizes in monoclinic system, space group P21/c, with a =3.888(3)Å, b =26.974(17)Å, c =14.940(9)Å, β =91.919(8)°, Z=8, whereas compound (2) crystallizes in orthorhombic system, space group Pbca, with a =7.255(2)Å, b =14.410(4)Å, c =18.332(1)Å, Z =8. The crystal packing of (1) exhibits intermolecular O–H···O hydrogen bonds forming a parallel chain propagating along (010) direction, whereas in (2), the combination of intermolecular C–H···O hydrogen bonds and π–π interactions generate a two-dimensional network. The molecular geometries and electronic structure of (1) and (2) were calculated at the DFT level using the hybrid exchange correlation functional, BLYP, PW91, PBE and BP. [Copyright &y& Elsevier]

• The molecular structures of two synthesized Cu(II)-PDA complexes have been studied using single-crystal X-ray diffraction. • Supramolecular networks in the crystal structures have been explored. • The noncovalent interactions are quantified through hirshfeld surface analysis. • AIM analysis and topological parameters characterize the intermolecular interactions. • Visual representation of noncovalent interactions is performed by NCI plot index. The structural study of two synthesized Cu-PDA (Cu = Copper(II), PDA = deprotonated Pyridine-2,6-dicarboxylic acid) complexes has been carried out using single-crystal X-ray diffraction where complex (1) [Cu(PDA)(H 2 O) 2 ] exhibits one-dimensional (1D) and two-dimensional (2D) supramolecular assemblies and complex (2) [Cu(PDA)(H 2 PDA)]·H 2 O exhibits 1D, 2D, and 3D (three-dimensional) supramolecular networks in their solid-state structure with the aid of intermolecular noncovalent interactions. Lone pair···π/π···lone pair networks are exclusively found in both complex (1) and (2). The intermolecular interactions are characterized through Hirshfeld surface analysis and quantified by 2D fingerprint plot. The noncovalent interactions are further characterized by Bader's theory of 'Atoms in Molecules' (AIM) and 'noncovalent interaction' (NCI) plot and the topological parameters at bond critical points (BCPs) have been evaluated. Therefore, the energetic factors to the stabilization of the crystal structure observed experimentally have been obtained by the computational calculations. [ABSTRACT FROM AUTHOR]

• Comparison of structural diversity of PDA and its di-hydrate has been explored. • The lattice energy of PDA outperformed 43.3% than its di-hydrate. • Electrostatic forces dominate in PDA and dispersion forces in its di-hydrate. • AIM's topological parameters reveal closed-shell nature of noncovalent interactions. • RBG color scheme of NCI analysis characterizes the nature of noncovalent interactions. Crystals of pyridine-2,6-dicarboxylic acid (1) have been structurally characterized through single-crystal X-ray diffraction analysis and compared with pyridine-2,6-dicarboxylic acid dihydrate ((2) retrieved from CSD), and explore the solid-state networks. In the solid state, compound (1) exhibits both hydrogen bonding and π···π interactions, while the supramolecular network of compound (2) is stabilized only by hydrogen bonding interactions. The non-covalent interactions are characterized by various computational studies such as Hirshfeld surface analysis, Bader's 'Atoms in Molecules' (AIM) theory, and 'Non-covalent interaction' (NCI) plot analysis. Hirshfeld surfaces and corresponding 2D fingerprint plots reveal the contribution of non-covalent interactions involved in the structure. Lattice energy framework calculations also are carried out for both compounds. The topological parameters of the AIM analysis suggest the 'closed-shell' nature of the non-covalent interactions. Further, NCI plots and scatter graphs (RDG vs sign (λ 2)ρ) characterize non-covalent interactions with a color scheme. [Display omitted] [ABSTRACT FROM AUTHOR]

Four benzaldehyde derivatives [ALD‐1: compound (1), ALD‐2: compound (2), ALD‐5: compound (3), ALD‐6: compound (4)] were taken to investigate their optical band gap by UV‐vis spectroscopy. Semiconducting devices were fabricated using these compounds to study their electrical properties. The current‐voltage (I–V) characteristics graph was obtained. Furthermore, the diode parameters were extracted by conventional methods to analyze the charge transport mechanism. From the dielectric study, a low dielectric constant was observed. Moreover, each compound's mobility and transit time were derived to compare the device performance of benzaldehyde derivatives. [ABSTRACT FROM AUTHOR]

Terpyridinium salts of hydracids [PTPH3](Br)3·H2O (1), [PTPH3](Cl)3·2H2O (2) and oxoacid [PTPH3](ClO4)3·H2O (3) (PTP = 4′-(3-pyridyl)-4,2′:6′,4′′-terpyridine) were synthesized and characterized using single crystal X-ray diffraction analyses. The crystallographic analysis reveals that the π+⋯π, π+⋯π+, anion⋯π and anion⋯π+ interactions play a crucial role in the stabilization of the self-assembled structure, which in turn is responsible for enhancing the dimensionality of all the compounds. All the compounds confirm their usefulness as optoelectronic devices owing to the pronounced electrical conductivity and photosensitivity. Experimental and theoretical observations clarify an increase in the electrical conductivity on irradiation compared to dark conditions, especially in 3. [ABSTRACT FROM AUTHOR]

The supramolecular frameworks of two metal complexes with 1,3-diamino-2-hydroxypropanetetraacetic acid (H 4 Hpdta) have been explored in the context of crystal engineering, and the noncovalent interactions are further characterized by Bader's quantum theory of "atoms-in-molecules" (QTAIM), Noncovalent Interaction (NCI) plot index and Scatter plot. [Display omitted] A new 1,3-diamino-2-hydroxypropanetetraacetate copper complex (1) [{Cu(Hpdta)}{Cu(H 2 O) 6 }] has been synthesized and structurally characterized by single crystal X-ray diffraction and compared with a similar cobalt complex (2) of H 4 Hpdta (H 4 Hpdta = 1,3-diamino-2-hydroxypropanetetraacetic acid) retrieved from CSD (CSD ref code: TELBAN) with a detailed analysis of intermolecular interactions. X-ray crystallography reveals that both complexes are stabilized through C−H⋯O and O−H⋯O interactions generating different supramolecular networks. Detailed analysis of Hirshfeld surfaces and 2D fingerprint plot has been carried out for the title complexes to quantify the intermolecular interactions. Further, the noncovalent interactions are characterized through the Bader's theory of 'Atoms in Molecules' (AIM) and noncovalent interaction (NCI) plot index. At the bond critical point (BCP), the electron density (ρ BCP) and the Laplacian of electron density ( ∇ 2 (ρ BCP)) differ significantly for strong and weak noncovalent interactions. The dissociation energies are evaluated for validating the intermolecular interactions required to stabilize the complexes. The analysis of topological parameters extracted from AIM calculation characterized the interactions as closed-shell interactions. [ABSTRACT FROM AUTHOR]

• Unconventional Cu⋯π interaction. • Bader's theory of 'atoms in molecules' (AIM) and AIM topology analysis. • 'Non-covalent interaction' (NCI) plot index analysis. • 'Intrinsic Bond Strength Index for Weak Interaction' (IBSIW). • 'Independent Gradient Molecule based on Hirshfeld partition' (IGMH). A copper-phenanthroline complex, namely [bis(μ 2 ‑chloro)-dichloro-bis(1,10-phenanthroline)-di-copper(II)] has been synthesized and structurally characterized by single-crystal X-ray diffraction. The X-ray structure of the complex is stabilized through the hydrogen bond, π⋯π, and Cu⋯π interactions. The Cu⋯π interactions of the title complex along with two other complexes (retrieved from CSD) are analyzed in great detail through various theoretical calculations. Hirshfeld surface analysis and fingerprint plot quantify the non-covalent interactions. The interaction energies associated with intermolecular interactions have been calculated based on QTAIM (Quantum Theory of atoms in molecule). The analysis of topological parameters of charge density at (3, −1) bond critical points characterize the interactions as "closed-shell" interactions. The non-covalent interactions are further characterized by the Non-Covalent Interaction (NCI) plot index, Independent Gradient Module based on Hirshfeld partition of molecular density (IGMH), and Intrinsic Bond Strength Index for Weak interaction (IBSIW). The supramolecular solid- state structure of the copper-phenanthroline complex by unconventional Cu∙∙∙π interaction is explored. Quantification of Cu∙∙∙π interaction as well as other non-covalent interactions has been analyzed through Hirshfeld surface analysis. Bader's theory of 'atoms in molecule' (AIM), 'Non-covalent interaction' (NCI) plot index, 'Independent Gradient Module based on Hirshfeld partition' (IGMH), 'Intrinsic Bond Strength Index for Weak interaction' (IBSIW) were used to characterize the Cu∙∙∙π and other non-covalent interactions. [Display omitted] [ABSTRACT FROM AUTHOR]

A series of pyridinium-carboxylate salts (1–3) were designed, synthesized and structurally characterized to explore the importance of salt-bridge (SB) interactions in building self-assembled structures. We present a comprehensive analysis of the SB interaction in crystal structures of 4,4′-oxybis(benzoic acid) with substituted aminopyridines where the SBs display extremely well defined geometric preferences. In the solid-state, compound (1) exhibits lone-pair (l.p)⋯(SB)/(SB)⋯π+ assemblies while compound (2) shows a C–H⋯(SB)/(SB)⋯π network. Interestingly, compound (3) exhibits two distinct networks π+⋯(SB)/(SB)⋯(SB)/(SB)⋯π+ and C–H⋯(SB)/(SB)⋯H–C. These extended supramolecular networks are studied and described in detail. The duality of the SBs in stabilizing the π-facial interactions with electron rich and/or electron poor moieties is also described. The energetic and geometric features of salt-bridge interaction are studied and its impact on the resultant supramolecular organization is analyzed using theoretical DFT-D3 calculations. The theoretical study combines the energetic features of the noncovalent forces that participate in the extended network and the characterization of the diverse interactions by means of Bader's theory of 'atoms in molecules'(AIM). [ABSTRACT FROM AUTHOR]

The supramolecular frameworks of two new Co(II)–PDA complexes have been explored in the context of crystal engineering, and the noncovalent interactions are further characterized by Bader's quantum theory of "atoms-in-molecules" (QTAIM), Noncovalent Interaction (NCI) plot index and Scatter plot, and optically characterized by UV–Vis spectroscopy. [Display omitted] Two new Co(II) complexes, {[Co(2,6-pydc) 2 ]·[Co(4,4′-tmdpy)(H 2 O) 4 ] n ·2H 2 O}(1) and {2[ Co (2,6- pydc) 2 ]2-·[2(4,4′-bpy]2+·10(H 2 O)·O}(2) [2,6-pydc = 2,6-pyridinedicarboxylic acid, 4,4′-tmdpy = 4,4′-trimethylenedipyridine, 4,4′-bpy = 4,4′-Bipyridine] were designed, synthesized, and characterized using elemental analysis, spectroscopic techniques, and single-crystal X-ray diffraction analysis. For complex (1), hydrogen bonding, π⋅⋅⋅π and lone pair (l.p.)···π interactions produce supramolecular assemblies, whereas for complex (2), hydrogen bonding, π⋅⋅⋅π, π⋅⋅⋅π+, π+⋅⋅⋅π, l.p···π play the pivotal role in building final solid-state structure. Complex (1) exhibits a unique 3D supramolecular architecture generated through π⋅⋅⋅π and l.p···π interactions. Complex (2) also exhibits a unique (l.p···π/π⋅⋅⋅π+/π+⋅⋅⋅π/π⋅⋅⋅π/π⋅⋅⋅π+/π+⋅⋅⋅π/π⋅⋅⋅l.p) n self-assembly. The noncovalent interactions were characterized through Bader's quantum theory of "Atoms In Molecules" (QTAIM). Evaluation of topological parameters at (3, –1) bond critical points (BCPs) confirmed the 'closed-shell' nature of the intermolecular interactions. Furthermore, the theoretical "Noncovalent Interaction" (NCI) plot index was used to characterize noncovalent interactions. [ABSTRACT FROM AUTHOR]

• Hexamethylenetetramine derivatives. • Supramolecular self-assembly of the X-ray structures. • Theoretical DFT calculation to explore the energetic features of non-covalent interactions. • Bader's theory of atoms in molecules (AIM) to characterize the non-covalent interaction. • Theoretical Non-covalent interaction (NCI) plot index to characterize the non-covalent interaction. • Optical characterization to estimate the band gap. Two octahedral hexaaqua complexes, namely hexa-aqua-cobalt(II) dinitrate bis(hexamethylenetetramine) tetrahydrate and hexa-aqua-mangnesium(II) dinitrate bis(hexamethylenetetramine) tetrahydrate [MII(H 2 O) 6 ](HMTA) 2 (NO 3) 2.4H 2 O [M= Co (complex (1)) and Mg (complex (2))] have been synthesized. The crystal structures of the title complexes were determined by single-crystal X-ray diffraction. The X-ray crystallography study reveals that O−H···O and O−H···N play a pivotal role in building the supramolecular structures in both complexes. Theoretical DFT calculations have calculated the energies associated with hydrogen bonding interactions. These non-covalent interactions are characterized based on Bader's theory of "atoms in molecules" (AIM). The analysis of topological parameters of electron density at the (3, −1) bond critical point classified the interactions as "closed-shell" interactions. Further characterization of non-covalent interactions has also been performed by the "non-covalent interaction" plot index (NCI). Optical characterization has been performed to measure the band gap. The supramolecular solid-state structures of two metal-organic have been explored. The energetic features of non-covalent interactions have been examined. Bader's theory of 'atoms in molecules' (AIM) and 'non covalent interaction' (NCI) plot index were used to characterize the non-covalent interaction. [Display omitted] [ABSTRACT FROM AUTHOR]

In this article, ab initio calculations have been combined with a search in the Protein Data Bank (PDB) to demonstrate the importance of σ-hole tetrel bonding interactions in biological systems. In particular, we focus our attention on the ability of the -CF3 group to participate in noncovalent interactions as Lewis acids, and we show the importance of this interaction in the inhibition mechanism of a NADP+-dependent isocitrate dehydrogenase (IDH) enzyme that converts isocitrate to α-ketoglutarate. IDH mutations are found in multiple hematologic and solid tumors, inducing premalignant disorders. A potent triazine-based inhibitor of the mutant IDH (enasidenib) presents two-CF3 groups in the structure. One establishes a tetrel bonding interaction with an aspartate residue that contributes to the binding and selectivity of the inhibitor to the active site. [ABSTRACT FROM AUTHOR]

Crystals of penta(carboxymethyl)diethylenetriamine have been structurally characterized through single‐crystal X‐ray diffraction analysis. X‐ray diffraction analysis reveals that various non‐covalent interactions combine to determine the crystal packing and final solid‐state supramolecular assembling behavior. The title compound exhibited various 2D supramolecular networks generated through O−H⋅⋅⋅O and C−H⋅⋅⋅O interactions. The C−H⋅⋅⋅O interactions are pivotal in building a two‐dimensional framework, whose formation is readily analyzed with zero‐dimensional centrosymmetric dimeric rings as building blocks within the structure. All the intermolecular interactions are quantified through Hirshfeld surface analysis and fingerprint plots. Energy frameworks are constructed to analyze the dominant interaction energy involved in molecular packing strength. Bader's quantum theory of "atoms‐in‐molecules" (QTAIM) has been used to analyze and characterize non‐covalent interactions. The QTAIM analysis validates the existence of hydrogen bonding contacts, and the topological properties of bond critical points (BCPs), such as the electron density ρ(r) and its Laplacian ∇2ρ(r), are presented to correlate with the interaction energy. The topological analysis revealed that all of the interactions are closed‐shell interactions. Finally, the "Non‐covalent Interaction" (NCI) plot index illustrates the solid‐state supramolecular networks. [ABSTRACT FROM AUTHOR]

A new cadmium (II) complex, [Cd(4-Me-5-CHOIm)Cl] has been synthesized and characterized using single crystal X-ray diffraction study. The interaction of the complex with calf thymus DNA (CT-DNA) and double stranded RNA [polyinosinic·polycytidylic acid (poly(I)·poly(C)] has been investigated by various biophysical techniques. The interaction of the complex with CT-DNA and RNA displays a binding order of 10. Graphical Abstract: A new cadmium (II) coordination polymer, [Cd(4-Me-5-CHOIm)Cl] has been synthesized. The binding of the complex with double stranded DNA, RNA has been carried out by different spectroscopic techniques and energetic of the interaction was derived from isothermal titration calorimetry (ITC). [ABSTRACT FROM AUTHOR]

The synthesis and X-ray structural characterization of two silver(I) coordination polymers, [Ag2(bpp)2(Phdac)]·5H2O (1) and [Ag2(bpp)(HSSal)] (2), are reported, where bpp = 4,4′-trimethylene dipyridine, H2Phdac = 1,4-phenylenediacetic acid, and H3SSal = 5-sulfosalicylic acid. X-ray crystallography reveals that the structures are stabilized through hydrogen bonding interactions. The C–H⋯πand metal⋯πinteractions of aromatic molecules play a crucial role in building a layered framework. Intricate combinations of the weak non-covalent interactions have been analyzed to explore cooperativity and competitiveness in the solid-state structures. [ABSTRACT FROM AUTHOR]

The ligand 3,3-( p-phenylenedimethylene) bis{1-(2-methylallyl)} imidazolium bromide ( 1) and its Palladium(II) N-heterocyclic carbene (NHC) complex ( 3) has been synthesized and characterized by several spectroscopic techniques and the solid-state structure of 3 has been determined by single crystal X-ray diffraction studies. The Pd(II) complex possesses ring head to tail π- π stacking interactions (3.767 A ) through imidazole rings. Complex 3 catalyzes Suzuki-Miyaura 'C-C' coupling reaction. DFT calculations have been used to understand the HOMO/LUMO energy and hence the stability and reactivity of Pd(II) complex in syn and anti-configuration. [Figure not available: see fulltext. Caption: Palladium(II) N-heterocyclic carbene (NHC) complex ( 3) of the ligand 3,3'-(pphenylenedimethylene) bis{1-(2-methylallyl)}imidazolium bromide has been synthesized and characterized by several spectroscopic techniques and finally the solid-state structure of 3 has been determined by single-crystal X-ray diffraction studies. The Pd(II) complex possesses ring head to tail Π-Π stacking interaction (3.767 Ǻ) through imidazole rings. Complex 3 catalyzes Suzuki-Miyaura 'C-C' coupling reaction. DFT calculations were performed to know HOMO/LUMO energy and hence the stability and reactivity of Pd(II) complex in syn- and anti-configuration.] [ABSTRACT FROM AUTHOR]

• New binuclear monooxo, dioxo and tetramolecular tetraoxo bridging molybdenum(VI) complexes with ONS donor ligand has been synthesized. • Complexes give rise to interesting supramolecular architectures. • Hirshfeld surface analysis and fingerprint plots have been done for better understanding of non-covalent interactions. • 'Atoms in molecules' (QTAIM) along with 'non-covalent interaction' (NCI) plot index analyses have also been carried out. New Binuclear monooxo, Mo 2 O 4 L 2 1(H 2 O)CHCl 3 (1), tetranuclear tetraoxo, Mo 4 O 8 L 4 1 (2) and binuclear dioxo, Mo 2 O 4 L 2 2 (3) bridged molybdenum(VI) complexes have been synthesized using two diprotic tridentate ONS donor Schiff base ligands H 2 L1 and H 2 L2 (H 2 L1 = S - benzyl-β-N-(2-hydroxyphenyl) methylene dithiocarbazate and H 2 L2 = S - benzyl-β-N-(5‑bromo-2-hydroxyphenyl) methylene dithiocarbazate. All the three complexes have been characterized by elemental analyses and IR, UV–vis and 1H NMR spectroscopies and their crystal structures were solved by single crystal X-ray diffraction technique. Complexes (1) and (3) crystallized in triclinic space group P-1 and complex (2) in monoclinic space group P2 1 /n. Complexes 1, 2 and 3 exhibit distorted octahedral geometry around Mo(VI) center. X-ray crystallography reveals that in the crystal packing of the complexes C–H···O, O–H···O, O–H···N, C–X···π (X = Br) and π···π stacking interactions cooperatively take part. A detailed analysis of Hirshfeld surfaces and fingerprint plots facilitates a comparison of intermolecular interactions which are crucial in building different supramolecular architectures of three molybdenum complexes. Crystal structure analysis supported with the Hirshfeld surface and fingerprint plots enabled the identification of the significant intermolecular interactions. The intermolecular interactions are further characterized by analyzing the topological parameters through Bader's theory of 'atoms in molecule' (QTAIM) along with the 'non-covalent interaction' (NCI) plot index. The investigation of topological parameters of electron density at the (3, −1) bond critical point classified the interactions as 'closed-shell' interactions. Using two diprotic tridentate ONS donor Schiff base ligands (H 2 L1 and H 2 L2), new binuclear monooxo, Mo 2 O 4 L 2 1(H 2 O)CHCl 3 (1), tetramolecular tetraoxo, Mo 4 O 8 L 4 1 (2) and binuclear dioxo, Mo 2 O 4 L 2 2 (3) bridging molybdenum(VI) complexes have been synthesized and structurally characterized. Complexes 1–3 give rise to interesting supramolecular architectures. Hirshfeld surface, fingerprint plots and AMI (atoms in molecules) analysis has also been done in order to acquire a better understanding of non-covalent interactions. [Display omitted] [ABSTRACT FROM AUTHOR]

Synthetic, structural and photophysical properties of carbazole functionalized novel procarbenic species 1-(methyl/picolyl)-3-(N-ethylcarbazolyl)-1H benzimidazoliumhexaflurophosphate (1 and 2) and their N-heterocyclic carbene (NHC) complexes of Ag(i) (3 and 4), Au(i) (5 and 6) and Au(iii) (7 and 8) are described. According to the solid-state structures, a linear coordination geometry of Ag(i)–NHC (4) and Au(i)–NHC (6) has been established by X-ray diffraction studies; whereas the Au(iii)–NHC complex (7) adopts the square planar geometry. The Au(iii)–NHC (7 and 8) complexes have been synthesized from Au(i)–NHC (5 and 6) by capitalizing on a novel disproportionation protocol. Furthermore, the Au–Ccarbene bonds in complexes 7 and 8 are inert towards changes in the oxidation state of the metal atom. All the proligands (1 and 2) and complexes (3–8) are luminescent at room temperature. [ABSTRACT FROM AUTHOR]

Abstract: Starting from the proligands 1-methyl-3-picolylbenzimidazoliumhexaflurophosphate (1) and 1-benzyl-3-picolylbenzimidazoliumhexaflurophosphate (2) Ag(I)–NHC complexes, 1-methyl-3-picolylbenz-imidazolylidenesilver(I)hexaflurophosphate (3) and 1-benzyl-3-picolylbenzimidazolylidenesilver(I)hexaflurophosphate (4) have been synthesized. PO2F2 bridged Ag(I)-bimetallic system (5 and 6) developed from 3 and 4 after treatment of AgPF6 and water. 1-Methyl-3-picolyl-benzimidazolylidene-gold(I)hexaflurophosphate(7) and 1-benzyl-3-picolylbenzimidazolylidenegold(I)hexaflurophosphate (8) have been synthesized by Ag–carbene transmetallation method. Further reaction of AgPF6 with 7 and 8 build up the heterobimetallic Ag(I)–Au(I) systems (9 and 10); significantly, PO2F2 unit holds two heterobimetallic Ag(I)–Au(I) units together. Solid state structures of 3, 5, 8 and 9 have been determined by X-ray diffraction studies. Closed shell d10–d10 interactions are ascertained by the luminescence of bimetallic systems 7–10 upon irradiation of UV light. [Copyright &y& Elsevier]

A mononuclear Cu(II) compound [Cu(OAc)(2,2'-dypam)2](ClO4) (1), where HOAc and 2,2'-dypam are, respectively, acetic acid and 2,2'-dipyridylamine, has been synthesized and characterized by single crystal X-ray diffraction analysis. The cations of 1 link by N-H ··· O hydrogen bonds to form infinite 1-D zig-zag chains, which run along the b axis. Two adjacent chains along the c axis are joined by C-H ··· O hydrogen bonds to form a 2-D network. These 2-D layers are further bridged by perchlorate anions via weak anion-π interactions that act as a supramolecular glue to build the 3-D supramolecular network. Variable temperature (1.7-300 K) magnetic measurements revealed very weak intermolecular antiferromagnetic interactions at temperatures below 20 K between Cu(II) ions mediated by hydrogen bonds, C-H ··· π and π ··· π interactions. At temperatures ≥20 K, susceptibility data corresponds to isolated Cu(II) ions, indicating that the weak interactions affect the magnetism of 1 only at very low temperatures. [ABSTRACT FROM AUTHOR]

• 4′-functionalized 2,2′:6′,2″-terpyridine derivatives have been synthesized and structurally characterized. • Supramolecular self-assembly of the X-ray structures are explored in detail in the context of crystal engineering. • Quantification of noncovalent interactions through Hirshfeld surface analysis. • Bader's theory of 'atoms-in-molecules'(AIM) have been performed to characterize the noncovalent interactions. • Theoretical 'Noncovalent Interaction' (NCI) plot index have been used to characterize the interactions that are involved within the structures. Three versatile 4′-substituted 2,2′:6′,2″-terpyridine compounds (1 – 3) having different substitutions (4-ethoxyphenyl, 4-methoxyphenyl and pyridyl) at 4′-position of the central pyridine ring have been synthesized and structurally characterized. Three representative crystal structures have been determined through single crystal X-ray diffraction analysis. X-ray crystallography revels that the structures are stabilized through C–H···π and π–π stacking interactions. In the solid-state, the supramolecular assemblies of the title compounds have been explored in detail. Compounds (1) and (3) exhibits both C–H···π and π–π interactions in building supramolecular assemblies whereas compound (2) exhibit π–π interaction only. All the intermolecular interactions that are involved within the structures are quantified through Hirshfeld surface analyses. The weak noncovalent interactions that played significant role in building supramolecular assemblies are further characterized by Bader's theory of 'atoms-in-molecules' (AIM). Finally, the supramolecular networks are characterized by theoretical 'Noncovalent Interaction' (NCI) plot index. The supramolecular solid-state frameworks of three 4′-functionalized 2,2′:6′,2″-terpyridine derivatives have been quantified which are further characterized theoretically by the Bader's theory of 'atoms-in-molecules'(AIM) and 'noncovalent interaction' (NCI) plot index. Image, graphical abstract [ABSTRACT FROM AUTHOR]