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• X-ray diffraction of a novel diphosphopentamolybdate (H 2 AEP) 4 [CoP 2 Mo 5 ] 2 is reported. • Refractive index shows significant dispersive behavior in the visible spectrum. • Temperature-dependent emission shows promise as a luminescent temperature sensor. • χ M.T indicates an antiferromagnetic exchange interaction. • DFT-based study confirms semiconducting behavior and antiferromagnetic coupling. This work reports the synthesis of a novel diphosphopentamolybdate compound with the formula (C 6 H 17 N 3) 4 [Co(H 2 O) 4 P 2 Mo 5 O 23 ] 2 ‧8·74H 2 O abbreviated as (H 2 AEP) 4 [CoP 2 Mo 5 ] 2. Characterization of this compound was carried out using various techniques, including X-ray diffraction, thermal analysis (TGA), and spectroscopies such as FT-IR, Raman, UV–visible, and fluorescence. The structural study reveals that the studied material crystallizes in the orthorhombic system Pca2 1 with lattice parameters of a = 18.6348(16) Å, b = 11.8613(10) Å, c = 35.074(3) Å, and volume V = 7752.5(11) Å3, and a number of formula units per primitive cell Z = 4. The crystal structure study reveals that the Strandberg anions (P 2 Mo 5 O 23)6− are connected to Co(II) octahedra through the terminal oxygen atoms of the PO 4 tetrahedra, creating 1-D anionic chains in the crystallographic direction [101]. The 1-(2-Aminoethyl)piperazinium (AEP) cations are located within the anionic framework to neutralize its negative charge. The magnetic characteristics of the compound were investigated by examining the temperature-dependent molecular susceptibility over the range of 2–300 K. The analysis revealed the presence of an antiferromagnetic exchange interaction. Moreover, the material's refractive index exhibited significant dispersive behavior within the visible spectrum, indicating its potential for use in visible optical communication devices. A first-principles density functional theory (DFT)-based computational study confirms the semiconducting behavior of (H 2 AEP) 4 [CoP 2 Mo 5 ] 2 , revealing that in the ground state, high-spin octahedrally coordinated Co2+ cations exhibit a very weak antiferromagnetic coupling along the [ Co (H 2 O) 4 P 2 M o 5 O 23 ] ∞ 4 − chains running in the crystal a direction. [Display omitted] [ABSTRACT FROM AUTHOR]

Heterometallic 3d–4f SMM [Co4Dy(OH)2(SALOH)5(chp)4(MeCN)(H2O)2] (1) has been deposited onto iron oxide nanoparticles (NPs) with an oleate self-assembled monolayer (SAM) as a surfactant. The obtained hybrid molecular-inorganic system 1-NP has been thoroughly characterized. The oleate SAM separates SMM 1 from the magnetic substrate to avoid the strong-coupling between the surface and molecule to ensure that 1 retains its magnetic properties in 1-NP. The magnetic properties of the hybrid system 1-NP have been characterized by element specific XMCD: the heterometallic SMM retains its magnetic properties on the surface of the iron oxide NPs while there is an enhancement of the magnetic properties of the NPs. [ABSTRACT FROM AUTHOR]

The heterometallic bridging potential of the anion of 1-(2-hydroxy-3-methoxybenzylidene)semicarbazide (HL) to CoII and four 4f ions was examined during a 4f ion coordination-driven cleavage of [Co2(μ-OH2)(O2CCMe3)4(HO2CCMe3)4] (Co2-Piv) and scrambling of pivalate anions from the starting material. Room-temperature reactions with four different lanthanide nitrate salts yielded [CoLnL(μ2-OOCCMe3)4(CH3OH)]·3CH3OH [Ln = Gd (1), Tb (2), Dy (3) and Ho (4)]. The formation in solution and the crystallization in the solid state indicated that the reactions inhibit any further aggregation of Co-Ln cores to higher order aggregates. After scrambling, the pivalate ions in [Co-Ln] show three types of coordination modes to sustain the dinuclear aggregates with varying degrees of distortion in the dinuclear entities bound to a single L− ion. Atom economy was maintained with respect to the pivalate ions as no external addition of these anions was made. The dc magnetic measurements revealed the presence of weak ferromagnetic interactions in complexes 1 and 2 and weak antiferromagnetic interactions in complexes 3 and 4. [ABSTRACT FROM AUTHOR]

We report the microwave assisted synthesis of a bidimensional (2D) MOF of formula [Dy(MeCOO)(PhCOO)2]n (1) and its magnetically diluted analogue [La0.9Dy0.1(MeCOO)(PhCOO)2] (1 d). 1 is a 2D material with single‐ion‐magnet (SIM) behaviour and 1 d is a multifunctional, magnetic and luminescent 2D material. 1 can be exfoliated into stable nanosheets by sonication. [ABSTRACT FROM AUTHOR]

A family of 3d–4f aggregates have been reported through guiding the dual coordination modes of ligand anion (HL−) and in situ generated ancillary bridge driven self‐assembly coordination responses toward two different types of metal ions. Reactions of lanthanide(III) nitrate (Ln=Gd, Tb, Dy, Ho and Yb), nickel(II) acetate and phenol‐based ditopic ligand anion of 2‐[{(2‐hydroxypropyl)imino}methyl]‐6‐methoxyphenol (H2L) in MeCN‐MeOH (3 : 1) mixture and LiOH provided five new octanuclear Ni‐4f coordination aggregates from two Ni2Ln2 cubanes. Single‐crystal X‐ray diffraction analysis reveals that all the members of the family are isostructural, with the central core formed from the coupling of two distorted [Ni2Ln2O4] heterometallic cubanes [Ni2Ln2(HL)2(μ3‐OH)2(OH)(OAc)4]+ (Ln=Gd (1), Tb (2), Dy (3), Ho (4) and Yb (5)). Higher coordination demand of 4f ions induced the coupling of the two cubes by (OH)(OAc)2 bridges. Variable temperature magnetic study reveals weak coupling between the Ni2+ and Ln3+ ions. For the Tb (2) and Dy (3) analogs, the compounds are SMMs without an applied dc field, whereas the Gd (1) analogue is not an SMM. The observation revealed thus that the anisotropy of the Ln3+ ions is central to display the SMM behavior within this structurally intriguing family of compounds. [ABSTRACT FROM AUTHOR]

In this paper we test a solvent-free microwave assisted synthesis method with a known Ni 7 complex, [Ni 7 (chp) 12 (OH) 2 (CH 3 OH) 6 ] (2), and then extended the method to a more complex ligand system. We prepare two new trinuclear Ni(II) complexes ([Ni 3 (chp) 4 (tBuSALOH) 2 (MeOH) 5 ] (4) and [Ni 3 (chp) 4 (iPrSALOH) 2 (MeOH) 6 ] (5)) and report here their characterization and magnetic properties. [ABSTRACT FROM AUTHOR]

Three LnIII‐based metal‐organic frameworks (MOFs), namely [(Me2NH2)[Ln(OBA)2](Hatz)(H2O)1.5]n [Ln = Dy (1), Er (2), Ho (3); H2OBA = 4, 4'‐oxybis(benzoate) acid, Hatz = 3‐amino‐1,2,4‐triazole], were synthesized with Hatz as the template. In the structure of the three MOFs, the dinuclear LnIII nodes are bridged by four oxygen atoms from syn, syn‐carboxylate groups and this model result in a long distance between Dy–Dy, about 4.143(7) Å. In addition, the terminal carboxylate groups force a sandwich‐like coordination environment. Slow relaxation of the magnetization can be observed for 1, indicative of a single‐molecule magnet (SMM) behavior. Three unusual LnIII‐based metal‐organic frameworks (MOFs) were successfully obtained, in which the dinuclear LnIII nodes are bridged by four oxygen atoms from syn, syn‐carboxylate groups. This model result in a long distance between Ln–Ln. But slow relaxation of the magnetization can be observed, indicative of a single‐molecule magnet (SMM) behavior. [ABSTRACT FROM AUTHOR]

The condensation reaction of salicylaldehyde or 2-hydroxynaphthaldehyde with a diamino organic group (Acridine Yellow or diaminoacridine) resulted in the Schiff-base ligands ACRI-1, ACRI-2 and ACRI-3, with the last two hitherto unknown. Fluorescent ACRI-1, ACRI-2 and ACRI-3 were designed to provide iminophenolic binding pockets for two transition metals and ferromagnetic exchange between the metals. Following our report on the complex [Co2(ACRI-1)2] ( 1Co), we report herein the reactions of ACRI-1, ACRI-2 and ACRI-3 with CoII and CuII salts, which afforded the new fluorescent complexes [Cu2(ACRI-1)2] ( 1Cu), [Co2(ACRI-2)2] ( 2Co), [Cu2(ACRI-2)2] ( 2Cu), [Co2(ACRI-3)2(H2O)4] ( 3Co) and [Cu2(ACRI-3)2] ( 3Cu). [ABSTRACT FROM AUTHOR]

The new diimine fluorescent ligand ACRI-1 based on a central acridine yellow core is reported along with its coordination complex [Co2( ACRI-1)2] ( 1), a fluorescent weak ferromagnet. Due to the strong fluorescence of the acridine yellow fluorophore, it is not completely quenched when the ligand is coordinated to CoII. The magnetic properties of bulk complex 1 and its stability in solution have been studied. Complex 1 has been deposited on highly ordered pyrolitic graphite (HOGP) from solution. The thin films prepared have been characterized by AFM, time-of-flight secondary ion mass spectrometry (TOF-SIMS), grazing incidence X-ray diffraction (GIXRD), X-ray absorption spectroscopy (XAS), X-ray magnetic circular dichroism (XMCD) and theoretical calculations. The data show that the complex is robust and remains intact on the surface of graphite. [ABSTRACT FROM AUTHOR]

Microwave-assisted synthesis has been used to obtain the family of dodecanuclear NiII complexes [Ni12(NO3)(MeO)12(MeC6H4CO2)9(MeOH)10(H2O)2][ClO4]2 ( 1), [Ni12(NO3)(MeO)12(BrC6H4CO2)9(MeOH)10(H2O)2][ClO4]2 ( 2), [Ni12(CO3)(MeO)12(MeC6H4CO2)9(MeOH)10(H2O)2]2[SO4] ( 3) and [Ni12(NO3)(MeO)12(MeC6H4CO2)9(MeOH)8(H2O)7][NO3]2 ( 4). They contain three {Ni4O4} cubane units which template around a central μ6 anion, either NO3− or CO32−. Their magnetic properties have been studied by superconducting quantum interference device (SQUID) magnetometry and high-field EPR measurements. The nanostructuration of the Ni12 species on mica surfaces is studied by AFM and grazing-incidence X-ray diffraction, which reveal the formation of polycrystalline thin layers. [ABSTRACT FROM AUTHOR]

The synthesis of molecular cluster pairs is a challenge for coordination chemists due to the potential applications of these species in molecular spintronics or quantum computing. The ligand H4L, 1,3-bis-(3-oxo-3-(2-hydroxyphenyl)-propionyl)-2-methoxybenzene, has been successfully used to obtain a series of such complexes using the basic Fe(III) trinuclear carboxylates as starting materials. Synthetic control has allowed the isolation of the two molecular cluster pairs that form the composite [Fe4O2(PhCO2)6(H2L)(pz)]2[Fe3O(PhCO2)5(py)(H2L)]2 (1). The dimers of trinuclear units, [Fe3O(PhCO2)5(H2O)(H2L)]2 (2) and [Fe3O(o-MePhCO2)5(H2L)(py)]2 (3), and the dimers of tetranuclear units, [Fe4O2(PhCO2)6(H2L)(pz)]2 (4) and [Fe4O2(o-MePhCO2)6(H2L)(pz)]2 (5), are presented here. The magnetic properties of the reported aggregates show that they are pairs of semi-independent clusters weakly interacting magnetically as required for two-qubit quantum gates. [ABSTRACT FROM AUTHOR]

The synthesis of a terbium-based 2D metal–organic framework (MOF), of formula [Tb(MeCOO)(PhCOO)2] (1), a crystalline material formed by neutral nanosheets held together by Van der Waals interactions, is presented. The material can be easily exfoliated by sonication and deposited onto different substrates. Uniform distributions of Tb-2D MOF flakes onto silicon were obtained by spin-coating. We report the luminescent and magnetic properties of the deposited flakes compared with those of the bulk. Complex 1 is luminescent in the visible and has a sizeable quantum yield of QY = 61% upon excitation at 280 nm. Photoluminescence measurements performed using a micro-Raman set up allowed us to characterize the luminescent spectra of individual flakes on silicon. Magnetization measurements of flakes-on-silicon with the applied magnetic field in-plane and out-of-plane display anisotropy. Ac susceptibility measurements show that 1 in bulk exhibits field-induced slow relaxation of the magnetization through two relaxation paths and the slowest one, with a relaxation time of τlf ≈ 0.5 s, is assigned to a direct process mechanism. The reported exfoliation of lanthanide 2D-MOFs onto substrates is an attractive approach for the development of multifunctional materials and devices for different applications. [ABSTRACT FROM AUTHOR]

In this paper we report the synthesis of an asymmetric Schiff base ligand derived from hydrazine and its Cu(II) trinuclear coordination complex, [Cu 3 (HYDRAV) 2 Cl 2 ] (HYDRAV-Cu). The ligand HYDRAVH 2 and the Cu(II) complex HYDRAV-Cu have been crystallographically characterized. HYDRAVH 2 contains a fluorescent naphthyl group and emission properties of both HYDRAVH 2 and HYDRAV-Cu are reported. The magnetic properties of HYDRAV-Cu have been investigated. Hydrazine is an excellent precursor for asymmetric Schiff base ligands that afford antiferromagnetic coupling as shown here for HYDRAV-Cu. [ABSTRACT FROM AUTHOR]

Three CuII complexes with cis-epoxysuccinate ligand were synthesized and structurally characterized: [Cu(ces)(phen)]2 (1), [Cu(ces)(bpy)]2 (2), and {[Cu2(ces)(pp)2(CH3OH)]}∞ (3), (ces = cis-epoxysuccinate, phen = 1,10-phenanthroline, bpy = 2,2'-bipyridine, and pp = 3-(2-pyridyl)pyrazole with pyrazolyl N-donor deprotonated). Structural analysis reveals that both 1 and 2 have the very similar dinuclear units that are extended by the intermolecular supramolecular interactions, such as C-H...O, C-H...πd aromatic π...π stacking interactions, to give rise to the higher-dimensional frameworks. Complex 3 has a two-dimensional (2D) layered structure that is further assembled to form a three-dimensional framework by the inter-layer C-H...O hydrogen-bonding and C-H...π interactions. A structural comparison with those of our previous work in the absence of auxiliary co-ligand suggests that the introduction of 2,2'-bipyridyl-like molecules plays an important role in constructing the final structures of 1-3. Magnetic measurements demonstrate that 1 and 2 exhibit ferromagnetic coupling with the corresponding J values of 1.8 cm-1 for 1 and 1.5 cm-1 for 2, whereas 3 shows more complicated magnetic coupling. [ABSTRACT FROM AUTHOR]

Four new lanthanide–carboxylate coordination polymers of the formula [Ln 3 L 4 (phen) 4 (H 2 O) 4 ](ClO 4 )·2H 2 O, (Ln = Dy ( 1 ), Tb ( 2 ), Ho ( 3 ) and Er ( 4 ), L = 2,3-naphthalenedicarboxylate and phen = 1,10-phenanthroline) were solvothermally synthesized. Their structures as well as magnetic and photoluminescent properties were completely investigated. Complexes 1 – 4 are isostructural and exhibit 1D ribbon-like chains with envelope-like sixteen-membered rings. The Dy III and Tb III complexes show the corresponding characteristic luminescence in the visible region and the Er III complex shows luminescence in the near-infrared region upon excitation with UV rays. Studies on the magnetic properties are reported. The Dy(III) analog complex 1 exhibits slow magnetic relaxation and could be a new example of a Dy(III) SMM (single molecule magnet). [ABSTRACT FROM AUTHOR]

Abstract: Assembly of two tripodal multicarboxylic ligands, namely rigid 3,4-bis(4-carboxyphenyl)-benzoic acid (H3 L1 ) and flexible 3,5-bis(4-carboxyphenoxy)-benzoic acid (H3 L2 ) with MnCl2 under hydrothermal conditions afforded two distinct metal-organic frameworks (MOFs), {[Mn3(L1 )2(H2O)4](H2O)2} n (1) and {[Mn3(L2 )2(H2O)4](H2O)4} n (2), respectively. Interestingly, both complexes possess different 3D networks of novel self-interpenetrating prototype, constructing from different 2D [Mn(COO)2] n polymeric motifs. Furthermore, the thermal and magnetic properties of 1 and 2 are studied. [Copyright &y& Elsevier]

Five new Cu(II) complexes have been prepared by employing 2,3-naphthalenedicarboxylic acid (H[sub 2]ndc) and different N-donor co-ligands, namely, [Cu(ndc)(H[sub 2]O)][sub n] (1), [Cu(ndc)(H[sub 2]O)2][sub n] (2), {[Cu[sub 1.5](ndc)(OH)(H[sub 2]O)[sub 2]]·2.5H[sub 2]O}[sub n] (3), {[Cu(ndc)(phen)(H[sub 2]O)]·CH[sub 3]OH}[sub n] (4) (phen = 1,10-phenanthroline), and {[Cu[sub 2](H[sub 0.5]ndc)[sub 2](4bpy)[sub 3]](ClO[sub 4])·2H[sub 2]O}[sub n] (5) (4bpy = 4,4'-bipyridine). Complex 1 displays a two-dimensional (2D) (4,6)-connected (3[sup 2].4[sup 4])[sub 2](3[sup 4].4[sup 2].6[sup 4].7[sup 5])(3[sup 4].4[sup 3].6[sup 4].7[sup 4]) coordination network. Complex 2 shows a 2D 3-connected hcb network which is further interlinked via the interlayered C-H ··· π interactions to result in a three-dimensional (3D) supramolecular network. Complex 3 is a one-dimensional (1D) coordination chain which is further interlinked by the C-H ··· π and π ··· πp interactions to lead to the formation of the final 3D supramolecular network. When the N-donor co-ligands phen and 4,4'-bipyridine (4bpy) were introduced, the 1D complex 4 and the 4-connected sql layered complex 5 were constructed, respectively. The final supramolecular frameworks of 4 (2D) and 5 (3D) are extended by hydrogen-bonding and C-H ··· π interactions. The structural diversity of the complexes was triggered by different reaction conditions and N-donor co-ligands. Moreover, the magnetic properties of the complexes have also been investigated and discussed. [ABSTRACT FROM AUTHOR]

Two isomorphic 3-D complexes with the formulas [M3(TPTA) (OH)2(H2O)4]n (M = Ni for 1 and Co for 2; H4TPTA = [1,1':4',1-terphenyl]-2',3,3,5'-tetracarboxylic acid) have been synthesized and magnetically characterized. Complexes 1 (NiII) and 2 (CoII) have the same 1-D rod-shaped inorganic SBUs but exhibit significantly different magnetic properties. Complex 2(CoII) is a 3-D arrangement of a 1-D CoII single-chain magnet (SCM), while complex 1(NiII) exhibits weak coupling. [ABSTRACT FROM AUTHOR]

To further explore the research of the coordination possibilities of lanthanide ions with m -/ p -hydroxybenzoic acid isomers in the presence of chelating N-donor ligand 1,10-phenanthroline (phen), six lanthanide supramolecular frameworks based on 3- and 4-hydroxybenzoic acids, namely [Dy( m -L)( m -HL)(phen)]·H 2 O ( 1 ) ( m -H 2 L = 3-hydroxybenzoic acid), [Ln( m -HL) 3 (phen)] (Ln = Gd for 2 and Tb for 3 ), [Ln( p -HL) 3 (phen)(H 2 O)] (Ln = Dy for 4 , Gd for 5 , and Tb for 6 ; p -H 2 L = 4-hydroxybenzoic acid), were synthesized and characterized. Structural analyses reveal that complex 1 has a two-dimensional (2-D) sheet structure while complexes 2 and 3 take the dinuclear structures in the 3-hydroxybenzoate derivatives. In the 4-hydroxybenzoate derivatives, complexes 4 – 6 are isostructural and incorporated by monomeric units. Finally, all the complexes exhibit three-dimensional (3-D) supramolecular frameworks ( bcu net for 1 ; bct nets for 2 , and 4 – 6 ; hex net for 3 ) with the aid of abundant hydrogen bonding, π⋯π and C–H⋯π interactions. The results reveal that the different positions of the –OH substituent and coordination modes of hydroxybenzoic acids adjust the final coordination networks. Moreover, the magnetic and luminescent properties of the complexes have also been investigated and discussed. [ABSTRACT FROM AUTHOR]

Assembly of a semi-rigid tripodal ligand, 3,5-bis(4-carboxyphenoxy)benzoic acid (H 3 bpa), with Ln 2 O 3 (Ln = Dy for 1 and Er for 2 ) under hydrothermal condition produces two three-dimensional (3-D) lanthanide–organic frameworks (LnOFs), [Dy 2 (bpa) 2 (H 2 O) 3 ] ( 1 ) and [Er 4 (bpa) 4 (H 2 O) 6 ](H 2 O) ( 2 ). Single crystal X-ray diffraction indicates that LnOFs 1 and 2 involve different one-dimensional (1-D) rod-shaped metal-carboxylate secondary building units (SBUs), which are further extended to afford two different 3-D frameworks via the linkage of bpa 3 − ligands. The results demonstrate that the diverse conformations and coordination modes of bpa 3 − ligands play a key role on the formation of the final framework structures. Temperature-dependent magnetic susceptibility measurements reveal the presence of Ln III ⋯Ln III ferromagnetic interactions in both LnOFs. [ABSTRACT FROM AUTHOR]

The work in this paper presents syntheses, characterization, crystal structures, variable-temperature/field magnetic properties, catecholase activity, and electrospray ionization mass spectroscopic (ESI-MS positive) study of five copper(II) complexes of composition [CuII2L(μ1,1-NO3)(H2O)(NO3)](NO3) (1), [{CuII2L(μ-OH)(H2O)}(μ-ClO4)]n(ClO4)n (2), [{CuII2L(NCS)2}(μ1,3-NCS)]n (3), [{CuII2L(μ1,1-N3)(ClO4)}2(μ1,3-N3)2] (4), and [{CuII2L(μ-OH)}{CuII2L(μ1,1-N3)}{CuII(μ1,1-N3)4(dmf)}{CuII2(μ1,1-N3)2(N3)4}]n·ndmf (5), derived from a new compartmental ligand 2,6-bis[N-(2-pyridylethyl)formidoyl]-4-ethylphenol, which is the 1:2 condensation product of 4-ethyl-2,6-diformylphenol and 2-(2-aminoethyl)pyridine. The title compounds are either of the following nuclearities/topologies: dinuclear (1), dinuclear-based one-dimensional (2 and 3), tetranuclear (4), and heptanuclear-based one-dimensional (5). The bridging moieties in 1-5 are as follows: μ-phenoxo-μ1,1-nitrate (1), μ-phenoxo-μ-hydroxo and μ-perchlorate (2), μ-phenoxo and μ1,3-thiocyanate (3), μ-phenoxo-μ1,1-azide and μ1,3-azide (4), μ-phenoxo-μ-hydroxo, μ-phenoxo-μ1,1-azide, and μ1,1-azide (5). All the five compounds exhibit overall antiferromagnetic interaction. The J values in 1-4 have been determined (-135 cm-1 for 1, -298 cm-1 for 2, -105 cm-1 for 3, -119.5 cm-1 for 4). The pairwise interactions in 5 have been evaluated qualitatively to result in ST = 3/2 spin ground state, which has been verified by magnetization experiment. Utilizing 3,5-di-tert-butyl catechol (3,5-DTBCH2) as the substrate, catecholase activity of all the five complexes have been checked. While 1 and 3 are inactive, complexes 2, 4, and 5 show catecholase activity with turn over numbers 39 h-1 (for 2), 40 h-1 (for 4), and 48 h-1 (for 5) in dmf and 167 h-1 (for 2) and 215 h-1 (for 4) in acetonitrile. Conductance of the dmf solution of the complexes has been measured, revealing that bridging moieties and nuclearity have been almost retained in solution. Electrospray ionization mass (ESI-MS positive) spectra of complexes 1, 2, and 4 have been recorded in acetonitrile solutions and the positive ions have been well characterized. ESI-MS positive spectrum of complex 2 in presence of 3,5-DTBCH2 have also been recorded and, interestingly, a positive ion [CuII2L(μ-3,5-DTBC2-)(3,5-DTBCH-)NaI]+ has been identified. [ABSTRACT FROM AUTHOR]

This investigation presents the syntheses, crystal structures, magnetic properties, and density functional theoretical modeling of magnetic behavior of two heterobridged μ-phenoxo-μ1,1-azido dinickel(II) compounds [NiII2(L1)2(μ1,1-N3)(N3)(H2O)]·CH3CH2OH (1) and [NiII2(L2)2(μ1,1-N3)(CH3CN)(H2O)](ClO4)·H2O·CH3CN (2), where HL1 and HL2 are the [1 + 1] condensation products of 3-methoxysalicylaldehyde and 1-(2-aminoethyl)-piperidine (for HL1)/4-(2-aminoethyl)-morpholine (for HL2), along with density functional theoretical magneto-structural correlations of μ-phenoxo-μ1,1-azido dinickel(II) systems. Compounds 1 and 2 crystallize in orthorhombic (space group Pbca) and monoclinic (space group P21/c) systems, respectively. The coordination environments of both metal centers are distorted octahedral. The variable-temperature (2-300 K) magnetic susceptibilities at 0.7 T of both compounds have been measured. The interaction between the metal centers is moderately ferromagnetic; J = 16.6 cm-1, g = 2.2, and D = -7.3 cm-1 for 1 and J = 16.92 cm-1, g = 2.2, and D(Ni1) = D(Ni2) = -6.41 cm-1 for 2. Broken symmetry density functional calculations of exchange interaction have been performed on complexes 1 and 2 and provide a good numerical estimate of J values (15.8 cm-1 for 1 and 15.35 cm-1 for 2) compared to experiments. The role of Ni-N bond length asymmetry on the magnetic coupling has been noted by comparing the structures and J values of complexes 1 and 2 together with previously published dimers 3 (Eur. J. Inorg. Chem. 2009, 4982), 4 (Inorg. Chem. 2004, 43, 2427), and 5 (Dalton Trans. 2008, 6539). Our extensive DFT calculations reveal an important clue to the mechanism of coupling where the orientation of the magnetic orbitals seems to differ with asymmetry in the Ni-N bond lengths. This difference in orientation leads to a large change in the overlap integral between the magnetic orbitals and thus the magnetic coupling. DFT calculations have also been extended to develop several magneto-structural correlations in this type of complexes and the correlation aim to focus on the asymmetry of the Ni-N bond lengths reveal that the asymmetry plays a proactive role in governing the magnitude of the coupling. From a completely symmetric Ni-N bond length, two behaviors have been noted: with a decrease in bond length there is an increase in the ferromagnetic coupling, while an increase in the bond lengths leads to a decrease in ferromagnetic interaction. The later correlation is supported by experiments. The magnetic properties of 1, 2, and three previously reported related compounds have been discussed in light of the structural parameters and also in light of the theoretical correlations determined here. [ABSTRACT FROM AUTHOR]