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Platinum‐based chemotherapeutic agents are widely used in the treatment of cancer. However, their effectiveness is limited by severe adverse reactions, drug resistance, and poor water solubility. This study focuses on the synthesis and characterization of new water‐soluble cationic monofunctional platinum(II) complexes starting from the [PtCl(η1‐C2H4OEt)(phen)] (1, phen=1,10‐phenanthroline) precursor, specifically [Pt(NH3)(η1‐C2H4OEt)(phen)]Cl (2), [Pt(1‐hexyl‐1H‐imidazole)(η1‐C2H4OEt)(phen)]Cl (3), and [Pt(1‐hexyl‐1H‐benzo[d]imidazole)(η1‐C2H4OEt)(phen)]Cl (4), which deviate from traditional requirements for antitumor activity. These complexes were evaluated for their cytotoxic effects in comparison to cisplatin, using immortalized cervical adenocarcinoma cells (HeLa), human renal carcinoma cells (Caki‐1), and normal human renal cells (HK‐2). While complex 2 showed minimal effects on the cell lines, complexes 3 and 4 demonstrated higher cytotoxicity than cisplatin. Notably, complex 4 displayed the highest cytotoxicity in both cancer and normal cell lines. However, complex 3 exhibited the highest selectivity for renal tumor cells (Caki‐1) among the tested complexes, compared to healthy cells (HK‐2). This resulted in a significantly higher selectivity than that of cisplatin and complex 4. Therefore, complex 3 shows potential as a leading candidate for the development of a new generation of platinum‐based anticancer drugs, utilizing biocompatible imidazole ligands while demonstrating promising anticancer properties. [ABSTRACT FROM AUTHOR]

Under ultrasound irradiation in an ethanol solvent, a new coordination complex of Cu(II) was successfully synthesized within a 10-min timeframe through the treatment of an imidazole-based ligand (PDI) with a copper-containing salt. The formation of the complex was verified through elemental (CHN) analysis and FT-IR spectroscopy. Additionally, the supramolecular assembly and packing of atoms in the crystalline units of the copper complex were elucidated using single-crystal X-ray diffraction method. The synthesized compound exhibits an ionic nature, featuring a copper(II) cation inside the coordination sphere and a chloride anion outside of the coordination sphere. The coordination environment around the copper cation is achieved through the bonding of the N-atom of the non-protonated PDI ligands and a chloride ion. To maintain a neutral charge, a second chloride ion serves as a counterion. The bond angles surrounding the Cu(II) ion showed a somewhat deformed square planar geometry of the complex. The non-covalent intermolecular interactions were executed by Hirshfeld surface analysis (HSA), while the theoretical studies were conducted using DFT employing the B3LYP/Def2-TZVP level of theory. The consistency between the theoretical findings and experimental data attested to the reliability of the theoretical conclusions. [ABSTRACT FROM AUTHOR]

This work presents the synthesis and characterization of two new transition metal coordination polymers [Co(tib)2](NO3)2 (1, tib = 1,3,5-tris(1-imidazolyl)benzene) and [Cd4(bib)5(HCOO)8](DMF)3 (2, bib = 4,4′-bisimidazolylbiphenyl) have been successfully prepared by using two imidazole-containing ligands with different geometers. All structures have been fully elucidated by single-crystal X-ray diffraction along with the elemental analysis. The structural solution and refinement results based on the crystal data collected at room temperature reveal that complex 1 shows a 2D layered structure with a binodal (3,6)-connected kgd topological net, while complex 2 also demonstrates a 2D framework but reflecting a 4-connected sql topological net. Furthermore, the anti-lung cancer activity of the two complexes has been studied via the Cell Counting Kit-8 (CCK-8) assay along with the corresponding action mechanism. [ABSTRACT FROM AUTHOR]

The new cluster compound [Nb6Cl12(HIm)6](OAc)2 · 3MeOH represents the first example of network compounds consisting of hexanuclear niobium cluster cations and acetate anions, which are connected though hydrogen bonds (besides Coulomb interactions). Hydrogen-bonded cation-anion pairs form chains, which are further extended to sheets by additional hydrogen bonds to co-crystallized methanol molecules. The synthesis of the title compound is based on a one-pot dehydration reaction of the cluster precursor [Nb6Cl14(H2O)4] · 4H2O with acetic anhydride in the presence of imidazole at T = 40°C. [ABSTRACT FROM AUTHOR]

A new nontoxic porous InIII‐based metal‐organic framework [In(Hpbic)(pbic)](DMF)2 (1) (DMF = N,N‐dimethylacetamide) was successfully prepared with 2‐(pyridin‐4‐yl)‐1H‐benzo[d]imidazole‐5‐carboxylic acid (H2pbic) as organic linker via a solvothermal process. Further, the nanostructure 1 could be obtained via a green grinding method. Nitrogen adsorption measurements revealed the presence of micropores as well as moderate high BET surface areas in the activated nanostructure 1 (1a). The drug loading experiment shows that 5‐fluorouracil (5‐Fu) is preferentially captured into the pore of the nanostructure 1a with a loading capacity of 32.6 %. Meanwhile, the controlled release of 5‐Fu in a simulated human body with liquid phosphate‐buffered saline solution was realized. In addition, the Cell Counting Kit‐8 (CCK‐8) assay was conducted to determine the inhibitory effect of 5‐Fu@1a on human colon cancer cell SW60 viability and proliferation, the results indicated the excellent anti‐cancer activity of 5‐Fu@1a in vitro. To reveal the related mechanism, the Annexin V‐FITC/PI assay and reactive oxygen species (ROS) level detection was carried out after 5‐Fu@1a treatment. Finally, the in vivo xenograft model was constructed in mice, the tumor volume, and mice body weight were recording at indicated time. The in vivo results suggested the significant inhibitory activity of 5‐Fu@1a in mice. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The structures of five nickel(II) tris-imidazolylphosphine complexes are reported. • The nickel complexes can be interconverted by altering the solvent or reagents. • The electronic structures of these complexes have been characterized by DFT. Abstract In this work we report the synthesis of five new nickel(II) complexes all coordinated to the tripodal ligand tris(1-ethyl-4- i Pr-imidazolyl)phosphine (T1Et4iPrIP). They are [Ni(T1Et4iPrIP)(CH 3 CN) 2 (OTf)](OTf) (1), [Ni(T1Et4iPrIP)(OTf) 2 ] (2), [Ni(T1Et4iPrIP)(H 2 O)(OTf)](OTf) (3), [Ni(T1Et4iPrIP)Cl](OTf) (4), and [Ni(T1Et4iPrIP)Cl 2 ] (5). The complexes serve as bioinorganic structural model complexes for histidine-coordinated nickel proteins. The X-ray structures have been determine for all complexes which feature coordination numbers 4–6. We investigated the spectroscopic interconversions for these compound in dichloromethane solution and demonstrate interconversion between 1 and 3 via 2 and conversion of 2 to 4. Complex 5 can be spectroscopically converted to the cation of 4 by dissolving it in dichloromethane. Fits of variable temperature magnetic susceptibility data yielded the following parameters: g = 1.944, D = −0.327 cm−1, E / D = 3.706 for 1 ; g = 2.280, D = −0.365 cm−1, E / D = 22.178 for 2 ; g = 2.000, D = −7.402 cm−1, E / D = −0.272 for 3 ; g = 2.176, D = −0.128 cm−1, E / D = −0.783 for 4 ; g = 2.258, D = 14.288 cm−1, E / D = 0.095 for 5. DFT structure optimizations afforded HOMO and LUMO energies indicating that complex 1 is the most stable. [ABSTRACT FROM AUTHOR]

We present the synthesis, properties, and characterization of [Fe(T1Et4iPrIP)(NO)(H2O)2](OTf)2 (1) {T1Et4iPrIP = Tris(1‐ethyl‐4‐isopropyl‐imidazolyl)phosphine} as a model for the nitrosyl adduct of gentisate 1,2‐dioxygenase (GDO). The further characterization of [Fe(T1Et4iPrIP)(THF)(NO)(OTf)](OTf) (2) which was previously communicated (Inorg. Chem. 2014, 53, 5414) is also presented. The weighted average Fe–N–O angle of 162° for 1 is very close to linear (≥ 165°) for these types of complexes. The coordinated water ligands participate in hydrogen bonding interactions. The spectral properties (EPR, UV/Vis, FTIR) for 1 are compared with 2 and found to be quite comparable. Complex 1 closely follows the relationship between the Fe–N–O angle and NO vibrational frequency which was previously identified for six‐coordinate {FeNO}7 complexes. Liquid FTIR studies on 2 indicate that the ν(NO) vibration position is sensitive to solvent shifting to lower energy (relative to the solid) in donor solvent THF and shifting to higher energy in dichloromethane. The basis for this behavior is discussed. The Keq for NO binding in 2 was calculated in THF and found to be 470 m–1. Density functional theory (DFT) studies on 1 indicate donation of electron density to the iron center from the π* orbitals of formally NO–. Such a donation accounts for the near linearity of the Fe–N–O bond and the large ν(NO) value of 1791 cm–1. We report a model for the iron–nitrosyl adduct of gentisate dioxygenase {[Fe(T1Et4iPrIP)(NO)(H2O)2](OTf)2, 1}. Complex 1 is synthesized by the addition of 2 equiv. water to [Fe(T1Et4iPrIP)(THF)(NO)(OTf)](OTf) (2). A correlation between the solid‐state Fe–N–O angle and ν(NO) is elaborated and the Keq in THF for the reversible binding of NO to 2 is reported. The influence of solvent on the value of ν(NO) for 2 is also discussed. [ABSTRACT FROM AUTHOR]

Two coordination polymers, {[Zn3(BTC)2(timb)2]·6H2O}n(1) and {[Co3(BTC)2(timb)2(H2O)4]·4H2O}n(2) (H3BTC = 1,3,5-benzenetricarboxylic acid and timb = 1,3,5-tris(imidazol-1-ylmethyl)benzene), have been synthesized and characterized by IR spectroscopy, elemental analysis and single-crystal X-ray diffraction. Structural analyses reveal that complex 1 exhibits a three-dimensional (3D) (3,4)-connected framework with an unusual (6.82)2(62.84)3(62.8)2topology, whereas complex2possesses a two-dimensional (3,4)-connected framework with a rare (4.82)4(46)2(84.122) topology. The results show that metal ions have significant effects on the formation and structures of the resulting complexes. Their thermal stability and photoluminescent properties were also investigated. [ABSTRACT FROM AUTHOR]

Polysiloxane microspheres containing a large number of silanol groups were obtained by an emulsion process of modified polyhydromethylsiloxane. N-substituted imidazole groups were grafted on these microspheres by the of their silanol groups with N-[γ-(dimethylchlorosilyl)propyl]imidazole hydrochloride. The progress of the reaction was monitored using 29Si and 13C magic angle spinning (MAS) NMR and its impact on microsphere morphology was studied using scanning (SEM). The usefulness of the imidazole-functionalized microspheres as a support for a metal catalyst was demonstrated by their reaction with PdCl2(PhCN)2. In this way a new heterogenized catalyst, Pd(II) complex with imidazole ligands supported on polysiloxane microspheres, was generated. This catalyst, MPd, was characterized using 13C and 29Si MAS NMR, X-ray photoelectron, Fourier transform infrared and far-infrared spectroscopies, X-ray diffraction, SEM-energy-dispersive X-ray spectroscopy and wide-angle X-ray scattering. The catalyst appears in two structures, as Pd(II) complex and Pd(0) nanoclusters. Its was tested using a model reaction, the of cinnamaldehyde, and compared with that of an analogous complex operating in a homogeneous system. MPd showed a high activity in the promotion of of cinnamaldehyde. The activity in the substrate conversion was stable at least in five cycles of this reaction. The main product was hydrocinnamaldehyde which could be obtained with a yield above 70%. A mechanism of the reaction is proposed. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

New silver(I) complexes [Ag 7 ( μ 4 -Cl)( μ 3 -Cl) 2 ( μ 2 -Cl) 3 (MPI) 6 ] ( 1 ), and [Ag( μ 3 -I)(BI)] n ( 2 ) [MPI = 1-(4-methoxyphenyl)-1 H -imidazole; BI = 1-Benzylimidazole] have been prepared starting with AgX (X = Cl, I) and 1-(4-methoxyphenyl)-1 H -imidazole/1-Benzylimidazole. The complexes have been characterized by elemental analysis, IR, 1 H NMR, and electronic absorption spectroscopy. Molecular structure of the complexes 1 and 2 were determined crystallographically. Complex 1 has a twofold axis with Ag3 in special position and bisecting the Ag4–Ag4′ vector. It contains six 1-(4-methoxyphenyl)-1 H -imidazole molecules and seven chlorine atoms bridging the seven silver atoms. Complex 2 exists as a one-dimensional (1D) polymeric chain of [( μ 3 -I)Ag( μ 3 -I)Ag] fragments bridged via the 1-Benzylimidazole ligand. The weak argentophilic Ag⋯Ag interaction distances in complexes 1 and 2 are 3.1014(4) Å–3.2998(15) Å, respectively. The complexes 1 and 2 , yielded silver oxide nanoparticles on pyrolysis and were characterized by PXRD and TEM. The catalytic properties of the resulting silver oxide nanoparticles and the silver(I) complexes have also been studied for A 3 -coupling of amines, alkynes and aldehydes in microwave which gave moderate to good yields of propargylamines. Silver(I) complexes exhibit higher catalytic activity compared to silver oxide nanoparticles. The silver oxide nanoparticles as well as silver(I) complexes could be separated easily from the reaction mixture and reused at least four to five times without significant loss of the catalytic activity. [ABSTRACT FROM AUTHOR]

In the coordination polymer catena-poly[[[diaqua[5-carboxy-2-(pyridin-3-yl)-1 H-imidazole-4-carboxylato-κ2 N3, O4]lead(II)]-μ-5-carboxy-2-(pyridin-3-yl)-1 H-imidazole-4-carboxylato-κ3 N3, O4: N2] dihydrate], {[Pb(C10H6N3O4)(H2O)2]·2H2O} n, the two 5-carboxy-2-(pyridin-3-yl)-1 H-imidazole-4-carboxylate ligands have different coordination modes, one being terminal and the other bridging. The bridging ligand links PbII cations into one-dimensional coordination polymer chains. The structure is also stabilized by intra- and interchain π-π stacking interactions between the pyridine rings, resulting in the formation of a two-dimensional network. Extensive hydrogen-bonding interactions lead to the formation of a three-dimensional supramolecular network. [ABSTRACT FROM AUTHOR]

Graphical abstract: Three new discrete dinuclear metallocyclic complexes have been synthesized by choosing the different flexible exo-bidentate imidazole-containing ligands with corresponding palladium salts. Compound 4 exhibits a [4+2] lantern-like cage structure. Complex 5 shows a 1D channel and complex 6 presents a 2D undulating framework. Display Omitted Highlights: [•] Three Pd(II) complexes with the flexible exo-bis(imidazole) ligands are synthesized. [•] Structural diversities are demonstrated. [•] Significant effects of the additional functional sites of chosen ligands are investigated. [•] The non-covalent interactions are discussed. [Copyright &y& Elsevier]

Abstract: Mixed ligand approach could be successfully applied to design porous three-dimensional coordination polymers, involving 1,3-bis(imidazol-1-yl)benzene (1,3-bib) as ligand. Five novel Co(II) compounds with different dimensionality have been synthesized. Utilizing only 1,3-bib in the solvothermal reaction with Co(II) salts, only molecular dimer Co2(bib)2Cl4 or 1D polymer Co2(1,3-bib)2(NO3)2 could be synthesized. Copolymerization technique using additional linear dicarboxylates 1,4-benzenedicarboxylate (1,4-bdc) or 2,6-naphthalenedicarboxylate (2,6-ndc) facilitates the formation of 2D layered coordination polymers Co(1,3-bib)(1,4-bdc) and Co(1,3-bib)(2,6-ndc). Utilizing 4,4′-biphenyldicarboxylate (4,4′-bpdc) as a co-linker, a 3D metal–organic framework Co3(1,3-bib)(4,4′-bpdc)3 (DUT-58, DUT – Dresden University of Technology), possessing two interpenetrated uninodal 8-connected frameworks, has been obtained. DUT-58 exhibits a specific surface area of 1208m2/g and adsorbs 27mg/g hydrogen (maximum excess value at 30bar and 77K), 0.18g/g n-butane (at 293K) and 72mg/g methane (maximum excess value at 60bar and 298K). [Copyright &y& Elsevier]

Ru(III), Cu(II) and Zn(II) complexes of imidazole (ImzlH) have been synthesized in the supercages of zeolite-Y by flexible ligand method and characterized by spectroscopic (IR and UV-Vis) studies, XRD and thermogravimetric analysis, surface area, and pore volume measurements. These complexes were screened for their catalytic study towards the oxidation of ethylbenzene to a mixture of acetophenone, benzaldehyde and styrene using tert-butylhydroperoxide (TBHP) as an oxidant. A best-suited reaction condition has been optimized for these catalysts by varying the amount of the oxidant and catalyst, reaction time and volume of solvent for maximum transformation of ethylbenzene. Under the optimized reaction conditions, [Cu(ImzlH)]-Y gave 79.3% conversion after 1 h of reaction time. All these catalysts were more selective towards acetophenone formation. Among the prepared catalysts, zeolite encapsulated Cu(II) complex was found to be more active than the corresponding Ru(III) and Zn(II) complexes and all the complexes were stable enough to be reused. The catalytic activities of the neat complexes and metal exchanged zeolites were also compared with the zeolite encapsulated metal complexes. [ABSTRACT FROM AUTHOR]

Abstract: Mixed ligand approach could be successfully applied to design porous three-dimensional coordination polymers, involving 1,3-bis(imidazol-1-yl)benzene (1,3-bib) as ligand. Five novel Co(II) compounds with different dimensionality have been synthesized. Utilizing only 1,3-bib in the solvothermal reaction with Co(II) salts, only molecular dimer Co2(bib)2Cl4 or 1D polymer Co2(1,3-bib)2(NO3)2 could be synthesized. Copolymerization technique using additional linear dicarboxylates 1,4-benzenedicarboxylate (1,4-bdc) or 2,6-naphthalenedicarboxylate (2,6-ndc) facilitates the formation of 2D layered coordination polymers Co(1,3-bib)(1,4-bdc) and Co(1,3-bib)(2,6-ndc). Utilizing 4,4′-biphenyldicarboxylate (4,4′-bpdc) as a co-linker, a 3D metal–organic framework Co3(1,3-bib)(4,4′-bpdc)3 (DUT-58, DUT – Dresden University of Technology), possessing two interpenetrated uninodal 8-connected frameworks, has been obtained. DUT-58 exhibits a specific surface area of 1208m2/g and adsorbs 27mg/g hydrogen (maximum excess value at 30bar and 77K), 0.18g/g n-butane (at 293K) and 72mg/g methane (maximum excess value at 60bar and 298K). [Copyright &y& Elsevier]

Abstract: Two new cobalt(II) and zinc(II) coordination networks constructed from an anthracene based bis imidazole ligand, 9,10-bis(imidazol-1-ylmethyl)anthracene ligand (L), are reported. The compounds {[Co (HBTC2−) (L) (H2O)2]·H2O}∞(1) and {[Zn (HBTC2−) (L) (H2O)2]·H2O}∞(2) were synthesized under solvothermal conditions and structurally characterized by single X-ray diffraction analysis and thermogravimetric analysis. Both 1 and 2 have a one-dimensional covalently bonded (1D) zigzag chain structure that is linked into infinite two-dimensional (2D) sheets by inter-chain π···π stacking and hydrogen bonding. [Copyright &y& Elsevier]

Abstract: We have prepared and characterized a series of substituted imidazole ligands namely dmmppi, dmmpfpi, dmdmppi and dmdmpfpi. These compounds will readily undergo cyclometalation with iridium trichloride and form di-irrido and the six coordinated iridium(III) dopants of the substituted imidazole ligands. They emit green colour both in solid and in solution phase. The peak emission wavelength of the dopants (λ max =428–497nm) can be finely tuned depending upon the electronic properties of the phenyl, fluorophyenyl, methoxy phenyl and dimethoxyphenyl substituents as well as their positions in the imidazole ring. These iridium complexes namely Ir(dmmppi)2(pic) 1a, Ir(dmmpfpi)2(pic) 1b, Ir(dmdmppi)2(pic) 1c and Ir(dmdmpfpi)2(pic) 1d were characterized by 1H NMR, MS and elemental analysis. All these iridium complexes 1a–1d show unusual high HOMO levels (E HOMO =5.21–5.41eV) and high phosphorescence. These complexes emit green light with exceedingly high efficiency. [Copyright &y& Elsevier]

Abstract: New Ir(III) complexes with a variety of imidazole ligands have been synthesized and fully characterized. The phenylimidazole-based ligands ( L = dpi , tmspi where dpi =1,4-diphenylimidazole; tmspi =1-trimethylsilyl-4-phenylimidazole) were prepared from copper catalyzed N-arylation reaction with 4-phenylimidzole. Ir(III) μ-chloro-bridged dimer, ( L )2Ir(μ-Cl)2Ir( L )2, were then prepared according to Nonoyama method [M. Nonoyama, Bull. Chem. Soc. Jpn. 47 (1974) 767]. ( L )2Ir(acac) and ( L )2Ir(pic) were finally obtained from the reaction of the dimer with the ancillary ligand, acetylacetonate (acac) or picolinate (pic). The complex coordinated with L and acac, ( L )2Ir(acac), does not exhibit emission. On the other hand, the complex coordinated with pic, ( L )2Ir(pic), showed green luminescence. Between ( dpi )2Ir(pic) and ( tmspi )2Ir(pic), ( tmspi )2Ir(pic) showed stronger emission. Naturally, the phenylimidazole-based ligands are known to have high energy gaps than 2-phenylpyridine. We thus performed the theoretical calculations on these complexes to support their optical properties. The calculation results show that the LUMO energy level of dpi and tmspi ligands are similar which that of acac ligand in ( L )2Ir(acac) complexes, and it leads to the energy transfer from dpi amd tmspi ligand, resulting in non-radiative process. [Copyright &y& Elsevier]

The present paper describes a new tripodal ligand containing imidazole and pyridine arms and its first cis-[RuIII(L)(Cl)2]ClO4 complex (1). The crystal structure of 1 shows RuIII in a distorted octahedral geometry, in which two chloride ions, cis-positioned to each other, are coordinated besides the four nitrogen atoms from the tetradentate ligand L. The cyclic voltammogram of 1 exhibits three redox processes at −67, +73 and +200 mV versus SCE, which are attributed to the RuIII/RuII couple in the cis-[RuIII(L)(Cl)2]+, cis-[RuII(L)(H2O)(Cl)]+ and cis-[RuII(L)(H2O)2]2+, respectively. After chemical reduction (Zn(Hg) or EuII) only the cis-[RuII(L)(H2O)2]2+ species is observed in the cyclic voltammetry. Complex 1 absorbs at 470 nm (ϵ=1.4×103 mol−1 L cm−1), 335 nm (ϵ=7.9×103 mol−1 L cm−1), 301 nm (ϵ=6.7×103 mol−1 L cm−1) and 264 nm (ϵ=9.9×103 mol−1 L cm−1), in water solution (CF3COOH, 0.01 mol L−1, μ=0.1 mol L−1 with CF3COONa). Spectroelectrochemical experiments show a decrease of the bands at 335 and 301 nm, which are attributed to LMCT transitions from the chloride to the RuIII center and the appearance of a broad band at 402 nm ascribed to MLCT transition from the RuII center to the pyridine ligand. The lability of the water ligands in the cis-[RuII(L)(H2O)2]2+ species has been investigated using the auxiliary ligand pyrazine. Reactions in the presence of stoichiometric and excess of pyrazine yield the same species, cis-[RuII(L)(H2O)(pz)]2+, which exhibits a reversible redox process at 493 mV versus SCE and absorbs at 438 nm (ϵ=5.1×103 mol−1 L cm−1) and 394 nm (ϵ=4.2×103 mol−1 L cm−1). Experiments performed with a large excess of pyrazine gave a specific rate constant k1=(2.8±0.5)×10−2 M−1 s−1, at 25 °C, in CF3COOH, 0.01 mol L−1, μ=0.1 mol L−1 (with CF3COONa). [Copyright &y& Elsevier]

The hydrothermal reaction of H2MoO4, copper acetate and imidazole in water gave rise to the title compound [Cu(imi)2]4[(imi)2Mo8O26]·4H2O ( 1) as brown crystals. Single X-ray crystal analysis reveals that 1is built up from imidazole coordinated copper fragments and imidazole coordinated octamolybdate units. These dodec-nuclear clusters are assembled into one-dimensional chain through weak copper(I)–copper(I) interactions, and further attached into three-dimensional network in the packing via complex hydrogen bonding. [ABSTRACT FROM AUTHOR]