Two Supramolecular Nickel(II) Complexes: Syntheses,Crystal Structures and Solvent Effects

Two nickel(II) complexes, namely {[NiL(MeOH)(μ‐OAc)]₂Ni} · 2CH₂Cl₂ · 2MeOH ( 1 ) and {[NiL(EtOH)(μ‐OAc)]₂Ni} · 2EtOH ( 2 ) {H₂L = 5, 5′‐dimethoxy‐2, 2′‐[(ethylene)dioxybis(nitrilomethylidyne)]diphenol}, were synthesized and structurally characterized. Two trinuclear Ni^II complexes are both hexacoordinate around the central Ni^II atoms, showing octahedral coordination arrangements, and each complex comprises three divalent Ni^II atoms, two deprotonated L^2– ligands, in which four μ‐phenoxo oxygen atoms forming two [NiL(X)] (X = MeOH or EtOH) units, and coordinated and non‐coordinated solvent molecules. Complex 1 exhibits a 2D supramolecular network through intermolecular O–H ··· O, C–H ··· O and C–H ··· π interactions, whereas complex 2 forms an infinite 1D chain by intermolecular C–H ··· O hydrogen bonding interactions.     

Self‐Assembly,Spectroscopic and Electrochemical Studies of Nickel(II)‐4,8‐Diazaundecanediamide Complex

The self‐assembly of NiCl₂·6H₂O with a diaminodiamide ligand 4,8‐diazaundecanediamide (L‐2,3,2) gave a [Ni(C₉H₂₀N₄O₂)(Cl)(H₂O)] Cl·2H₂O ( 1 ). The structure of 1 was characterized by single‐crystal X‐ray diffraction analysis. Structural data for 1 indicate that the Ni(II) is coordinated to two tertiary N atoms, two O atoms, one water and one chloride in a distorted octahedral geometry. Crystal data for 1: orthorhombic, space group P 21nb, a = 9.5796(3) Å, b = 12.3463(4) Å, c = 14.6305(5) Å, Z = 4. Through NH···Cl–Ni (H···Cl 2.42 Å, N···Cl 3.24 Å, NH···Cl 158°) and OH···Cl–Ni contacts (H···Cl 2.36 Å, O···Cl 3.08 Å, OH···Cl 143°), each cationic moiety [Ni(C₉H₂₀N₄O₂) (Cl)(H₂O)]⁺ in 1 is linked to neighboring ones, producing a charged hydrogen‐bonded 1D chainlike structure. Thermogrametric analysis of compound 1 is consistent with the crystallographic observations. The electronic absorption spectrum of Ni(L‐2,3,2)²⁺ in aqueous solution shows four absorption bands, which are assigned to the ³A_2g → ³T_2g, ³T_2g → ¹Eg, ³T_2g → ³T_1g, and ³A_2g → ³T_1g transitions of triplet‐ground state, distorted octahedral nickel(II) complex. The cyclic volammetric measurement shows that Ni²⁺ is more easily reduced than Ni(L‐2,3,2)²⁺ in aqueous solution.     

Syntheses and Crystal Structures of Two Novel Linear Trinuclear Schiff Base Nickel(II) and Cadmium(II) Complexes

Two novel linear trinuclear Schiff base complexes, [Ni{Ni(C₁₇H₁₄Br₂N₂O₂)(NO₃)(H₂O)}₂] · 2MeOH · 2H₂O ( 1 ), and [Cd{Ni(C₂₅H₂₀N₂O₂)(CH₃COO)}₂] ( 2 ), were synthesized and characterized by elemental analyses, infrared spectroscopy, and X‐ray single crystal determinations. There are three bridges across the Ni‐M atom pairs (M is Ni for 1 , and Cd for 2 ) in each complex, involving two phenolate O atoms of a Schiff base ligand (N,N′‐bis(5‐bromosalicylidene)‐1,3‐propanediaminate (BSPD) for 1 and N,N′‐bis(2‐hydroxynaphthylmethenylimino)‐1,3‐propanediaminate (HNPD) for 2 ), and an O‐N‐O moiety of a μ‐nitrato group for 1 or an O‐C‐O moiety of a μ‐acetato group for 2 . In each of the complexes, the central M²⁺ is located on an inversion center and has an octahedral coordination involving four bridging O atoms from two Schiff base ligands in the equatorial plane and one O atom from each bridging nitrate or acetate group in the axial positions. The coordination around the terminal Ni²⁺ ions is also octahedral for 1 , but square pyramidal for 2 . The nitrate or acetate bridges linking the central and terminal metal ions are mutually trans. The Ni···M distances are 3.006(2) Å in 1 , and 3.175(2) Å in 2 .     

Intermolecular Interaction and Magnetic Coupling Mechanism of a Mononuclear Nickel(II) Complex

The mononuclear complex [Ni(HOphen)(OSO₃)(H₂O)₃] · 5H₂O (HOphen = 1, 10‐phenanthrolin‐2‐ol) was prepared and its single structure was determined by X‐ray crystallography. In this complex, the Ni^II ion has a distorted octahedral arrangement. Crystal structure analysis shows that two kinds of π–π stacking interactions and C–H ··· O short contact intermolecular interactions exist among the adjacent complexes. Fitting to the variable‐temperature magnetic susceptibility data gave the magnetic coupling constant, 2J = –0.98 cm^–1. Theoretical calculations, based on density functional theory (DFT) coupling with the broken‐symmetry approach (BS), revealed that the π–π stacking magnetic coupling pathways resulted in weak ferromagnetic interactions with 2J = 4.86 cm^–1 and 2J = 4.16 cm^–1, respectively, for the adjacent Ni^II ions with separations of 8.568(19) Å and 8.749(32) Å, respectively; whereas the magnetic coupling pathway of the C–H ··· O short contact intermolecular interaction led to a weak antiferromagnetic interaction with 2J = –17.62 cm^–1 for the adjacent Ni^II ions with a separation of 10.291(26) Å. The ferromagnetic coupling sign can be explained by the McConnell I spin‐polarization mechanism.     

Comparative Study of three Mononuclear Vanadium‐Aromatic 1, 2‐Diol Complexes: Structure,Characterization and Anti‐Proliferating Effects Against Cancer Cells

Three mononuclear vanadium complexes containing aromatic 1, 2‐diols (catechol and naphthalene‐2, 3‐diol) ligands,[V^IVO(cat)₂][1, 3‐HPDA]₂ · CH₃OH ( 1 ), [V^IVO(N‐2, 3‐D)₂][1, 3‐H₂PDA] ( 2 ), and [V^VO₂(N‐2, 3‐D)(1, 3‐HPDA)] · 1, 3‐PDA ( 3 ) (cat = catechol, N‐2, 3‐D = naphthalene‐2, 3‐diol, 1, 3‐PDA = 1, 3‐propanediamine) were synthesized and characterized by X‐ray diffraction, IR and UV/Vis spectroscopy, and cyclovoltammetry. X‐ray analysis reveals that the spatial frameworks of complexes 1 – 3 are all constructed by hydrogen bonds donated by [1, 3‐H_nPDA]ⁿ⁺ (n = 1, 2) cation, forming distinct chain structures. Complexes 1 and 2 are both in the non‐chiral form of VO(L)₂, but 2 crystallizes in the chiral space group (P6₅22), due to the symmetry element of spiral axis, whereas complex 3 contains both enantiomers of chiral VO₂(L₁)(L₂) units, but crystallizes in the non‐chiral space group (P$\bar{1}$ ). The electrochemical behavior of the three complexes is studied in comparison with that of the free ligands. Complex 1 shows a pair of potentials assigned to the redox behavior of vanadium, while complexes 2 and 3 exhibit no such redox potentials. Pharmaceutical screening of complexes 1 – 3 were carried out against three representative cancer cell lines: A‐549 (lung cancer), Bel‐7402 (liver cancer) and HCT (colonic cancer) by MTT [3‐(4, 5‐dimethylthiazoyl‐2‐yl)‐2, 5‐diphenyltetrazolium bromide] assay. The results show that the vanadium‐catechol complex 1 exhibits more obvious anti‐proliferating effects against the three cell‐lines, whereas the two vanadium‐N‐2, 3‐D complexes 2 and 3 basically display no such effects.     

Co(en)3[B4O5(OH)4]Cl·3H2O和[Ni(en)3][B5O6(OH)4]2·2H2O的合成、结构以及热力学性质

利用水热法合成了两种过渡金属配合物为模板剂的含水硼酸盐晶体Co(en)3[B4O5(OH)4]Cl·3H2O(1) 和 [Ni(en)3][B5O6(OH)4]2·2H2O (2),并通过元素分析、X射线单晶衍射、红外光谱及热重分析对其进行了表征。化合物1晶体结构的主要特点是在所有组成Co(en)33+, [B4O5(OH)4]2–, Cl– 和 H2O之间通过O–H…O、O–H…Cl、N–H…Cl和N–H…O四种氢键连接形成网状超分子结构。化合物2晶体结构的特点是[B5O6(OH)4]–阴离子通过O–H…O氢键连接形成沿a方向有较大通道的三维超分子骨架,模板剂[Ni(en)3]2+阳离子和结晶水分子填充在通道中。     

A Novel Dinuclear Nickel(II) Complex with Three Bridges of Cl–, OAc– and (‐OCH2CH2O‐) Group of N,N, N′, N′‐Tetrakis(2‐benzimidazolyl methyl‐1, 4‐di‐ethylene amino) Glycol Ether

The novel dinuclear Ni²⁺ complex [Ni₂(μ‐Cl)(μ‐OAc) (EGTB)]·Cl·ClO₄·2CH₃OH, where EGTB is N, N, N′, N′‐tetrakis (2‐benzimidazolyl methyl‐1, 4‐di‐ethylene amino)glycol ether, crystallizes in the orthorhombic space group Pnma with a = 15.272(2), b = 14.768(2), c = 22.486(3) Å, V = 5071.4(12) ų, Z = 4, D_calc = 1.414 g cm^?3, and is bridged by triply bridging agents of a chloride ion, an acetate and an intra‐ligand (‐OCH₂CH₂O‐) group. The nickel coordination geometry is that of a slightly distorted octahedron with a NiN₃O₂Cl arrangement of the ligand donor atoms. The Ni–Cl distance is 2.361(2) Å, and two Ni–O distances are 1.996(5) and 2.279(6) Å. The three Ni–N distances are 2.033(7), 2.060(6), and 2.166(6) Å with the Ni–N bond trans to an ether oxygen the shortest, the Ni–N bond trans to an acetate oxygen the middle and the Ni–N bond trans to Cl the longest.     

Synthesis and Crystal Structure of Two Succinato‐Bridged Macrocyclic Nickel(II) Complexes

Two dinuclear succinato‐bridged nickel(II) complexes [Ni(RR‐L)]₂(μ‐SA)(ClO₄)₂ ( 1 ) and [Ni(SS‐L)]₂(μ‐SA)(ClO₄)₂ ( 2 ) (L = 5, 5, 7, 12, 12, 14‐hexamethyl‐1, 4, 8, 11‐tetraazacyclotetradecane, SA = succinic acid) were synthesized and characterized by EA, Circular dichroism (CD), as well as IR and UV/Vis spectroscopy. Single crystal X‐ray diffraction analyses revealed that the Ni^II atoms display a distorted octahedral coordination arrangement, and the succinato ligand bridges two central Ni^II atoms in a bis bidentate fashion to form dimers in 1 and 2 . The monomers of {[Ni(RR‐L)]₂(μ‐SA)}²⁺ and {[Ni(SS‐L)]₂(μ‐SA)}²⁺ are connected by O–H ··· O and N–H ··· O hydrogen bonds into a 1D right‐handed and left‐handed helical chain along the b axis, respectively. The homochiral natures of 1 and 2 are confirmed by the results of CD spectroscopy.     

The Spin Gap Transition around 180 K Observed in a New Molecular Magnet based on the [Ni(mnt)2]– Monoanion and Substituted Benzylpyridinium

A new molecular magnet, [NO₂BrBzPyCH₃][Ni(mnt)₂] ( 1 ) ([NO₂BrBzPyCH₃]⁺ = 1‐(2′‐bromo‐4′‐nitrobenzyl)‐2‐methylpyridinium, and mnt^2– = maleonitriledithiolate), has been prepared and characterized by single crystal X‐ray diffraction and magnetic measurements. The Ni(III) ions of 1 form a quasi‐one‐dimensional alternating zig‐zag magnetic chain within a Ni(mnt)₂^– column by intermolecular Ni···S, Ni···Ni or π···π interactions, and the [NO₂BrBzPyCH₃]⁺ cations stack into a column via weak Br···O interaction, p···π stacking interactions and C‐H···O hydrogen bonds between the cations. Magnetic susceptibility measurements in the temperature range 1.8‐300 K show that 1 exhibits a spin‐gap transition around 180 K, and an antiferromagnetic interaction in the high‐temperature phase (HT) and spin gap behavior in the low‐temperature phase (LT). The transition for 1 is a second‐order phase transition as determined by DSC analyses.     

Syntheses and Structural Characterization of Four New Silver(I) Complexes with the N,N′(O)‐bidentate Bridging Ligands

Four new bridged silver(I) complexes, namely [Ag₂(μ₂‐teda)(μ₂‐fbc)₂] ( 1 ), [Ag₂(μ₂‐1,6‐dah)₂](bpdc) · 4H₂O ( 2 ), [Ag₂(μ₂‐2‐ap)(2‐ap)(bnb)] · 0.34H₂O ( 3 ), [Ag₂(μ₂‐pyc)₂(2‐apy)₂] · 0.5H₂O ( 4 ), have been synthesized and characterized by elemental analysis and crystallographic methods [fbc = 4‐fluorobenzoate, teda = triethylenediamine ( 1 ); bpdc = biphenyl‐4,4′‐dicarboxylate, 1,6‐dah = 1,6‐diaminohexane ( 2 ); bnb = 3,5‐binitrobenzoate, 2‐ap = 2‐aminopyrimidine ( 3 ); pyc = 3‐pyridinecarboxylate acid, 2‐apy = 2‐aminopyridine ( 4 )]. Complex 1 contains a 1D linear chain paralleling to the c‐axis, whereas in complex 2 silver(I) atoms were bridged by the 1,6‐dah ligand into a zigzag chain, further giving a 1D ribbon by weak Ag ··· Ag interactions. Complex 3 consists of a dinuclear silver(I) [Ag₂(μ₂‐2‐ap)(2‐ap)(bnb)] moiety and a lattice water molecule, forming a 3D network via a number of hydrogen‐bonding interactions such as N–H ··· O, N–H ··· N and C–H ··· O hydrogen bond and other weak interactions such Ag ··· Ag, Ag ··· N, N ··· O as well as O ··· O interaction. Similar to 3 , the asymmetric unit of 4 consists of one dinuclear silver(I) [Ag₂(μ₂‐pyc)₂(2‐apy)₂] moiety and half lattice water molecule, further generating a tetranuclear silver(I) {[Ag₂(μ₂‐pyc)₂(2‐apy)₂]₂ · H₂O} moiety. These moieties construct a 3D supramolecular network structure of 4 through N–H ··· O, O–H ··· O and C–H ··· O hydrogen bonds as well as other weak interactions such as Ag ··· O and N ··· O interactions.     

A Series of Transition Metal Coordination Polymers Bearing 1,4‐Phenylenediacetate

The reactions of transition metal salts or hydroxide with 1,4‐phenylenediacetic acid (H₂PDA) in the presence of ancillary ligands 4,4′‐bipyridine (4,4′‐bpy) or imidazole (Im) produced five coordination polymers with the empirical formula [M(PDA)(4,4′‐bpy)(H₂O)₂]_n [M = Mn ( 1 ), Ni ( 2 )], [Cu(PDA)(4,4′‐bpy)]_n · 2nH₂O ( 3 ), [Ni(PDA)(Im)₂(H₂O)₂]_n · nH₂O ( 4 ), and [Cu(PDA)(Im)₂]_n · 2nH₂O ( 5 ). Their structures were determined by single‐crystal X‐ray diffraction analyses. The isomorphous 1 and 2 present a two‐dimensional sheet constructed by two kinds of one‐dimensional chains of –Ni^II–PDA^2––Ni^II– and –Ni^II–4,4′‐bpy–Ni^II–. Compound 3 features dinuclear subunits, which are further connected by two PDA^2– ligands and two 4,4′‐bpy ligands along (001) and (011) directions, respectively, to build a two‐dimensional sheet with the topology (4².6⁷.8)(4².6) different from those of 1 and 2 . Both 4 and 5 show one‐dimensional chain structure. The difference of compound 4 and 5 is that the two carboxylato groups of PDA^2– in 4 adopt monodentate coordination modes, whereas the two carboxylato groups of PDA^2– in 5 chelate to the metal ions. Magnetic susceptibility data of 1 were measured. Magnetically, 1 presents a one‐dimensional chain with a weak antiferromagnetic interaction (J =–0.064 cm^–1) between the intrachain Mn^II atoms mediated by 4,4′‐bpy.     

Synthesis,Crystal Structure and Magnetic Behaviour of {[Co(dimb)2(H2O)2]·(NO3)2·(H2O)2}n

The title complex {[Co(dimb)₂(H₂O)₂]·(NO₃)₂·(H₂O)₂}_n ( 1 ) (dimb = 1,3‐di(imidazol‐1‐ylmethyl)‐5‐methylbenzene) has been hydrothermally synthesized by the reaction of dimb with Co(NO₃)₂·6H₂O in aqueous solution. The cobalt(II) atoms are linked by bridging dimb ligands to form 2D corrugated and wavy networks containing Co₄(dimb)₄ macrocyclic motifs. Two neighboring independent layers interlinked each other in a parallel fashion to construct three‐dimensional structure by O–H···O, N–H···O and C–H···O hydrogen bonds. Magnetic measurement shows the weak antiferromagnetic interaction with a one‐dimensional chain model in the range of 5–300 K, with J of –0.68 cm⁻¹.     

Silylene–Nickel Promoted Cleavage of B−O Bonds: From Catechol Borane to the Hydroborylene Ligand

The first 16 valence electron [bis(NHC)](silylene)Ni⁰ complex 1 , [(^TMSL)ClSi:→Ni(NHC)₂], bearing the acyclic amido‐chlorosilylene (^TMSL)ClSi: (^TMSL=N(SiMe₃)Dipp; Dipp=2,6‐Prⁱ₂C₆H₄) and two NHC ligands (N‐heterocyclic carbene=:C[(Prⁱ)NC(Me)]₂) was synthesized in high yield and structurally characterized. Compound 1 is capable of facile dihydrogen activation under ambient conditions to give the corresponding HSi‐NiH complex 2 . Most notably, 1 reacts with catechol borane to afford the unprecedented hydroborylene‐coordinated (chloro)(silyl)nickel(II) complex 3 , {[cat(^TMSL)Si](Cl)Ni←:BH(NHC)₂}, via the cleavage of two B−O bonds and simultaneous formation of two Si−O bonds. The mechanism for the formation of 3 was rationalized by means of DFT calculations, which highlight the powerful synergistic effects of the Si:→Ni moiety in the breaking of incredibly strong B−O bonds.     

A Novel Self‐assembled Nickel(II)‐Cerium(III) Heterotetranuclear Dimer Constructed from N2O2‐type Bisoxime and Terephthalic Acid: Synthesis,Structure, and Photophysical Properties

By self‐assembly of a Salamo‐type ligand H₂L [H₂L = 1,2‐bis(3‐methoxysalicylideneaminooxy)ethane] with Ni(OAc)₂ · 4H₂O, Ce(NO₃)₃ · 6H₂O, and H₂bdc (H₂bdc = terephthalic acid), a novel Ni^II‐Ce^III heterometallic complex, [{Ni(L)Ce(NO₃)₂(CH₃OH)(DMF)}₂(bdc)], was obtained. Two crystallographically equivalent [Ni(L)Ce(NO₃)₂(CH₃OH)(DMF)] moieties lie in the inversion center, and are linked by one bdc^2– ligand leading to a heterotetranuclear dimer, in which the carboxylato group bridges the Ni^II and Ce^III atoms. Moreover, the photophysical properties of the Ni^II‐Ce^III complex were studied.     

Synthesis,Structures, and Photocatalytic Properties of Zinc(II) and Cobalt(II) Supramolecular Complexes Constructed with Flexible Bis(thiabendazole) and Dicarboxylate Linkers

Three coordination complexes, namely, [Zn(btbp)(3‐npa)]_n ( 1 ), [Co(btbh)(3‐npa)]_n ( 2 ), and {[Co(btbb)(5‐nipa)(H₂O)] · H₂O}_n ( 3 ) (btbp = 1,3‐bis(thiabendazole)propane, btbh = 1,6‐bis(thiabendazole)hexane, btbb = 1,4‐bis(thiabendazole)butane, 3‐H₂npa = 3‐nitrophthalic acid and 5‐H₂nipa = 5‐nitroisophthalic acid) were synthesized under hydrothermal conditions and characterized by physicochemical and spectroscopic methods as well as by single‐crystal X‐ray diffraction. Complex 1 features a fascinating meso‐helical chain, which is further extended into a 2D supramolecular framework involving π ··· π stacking interactions. Complexes 2 and 3 show dinuclear structures. Complex 2 is further connected through C–H ··· O hydrogen bonding interactions to afford a 2D supramolecular layer, whereas complex 3 is further extended to a rare 2‐nodal (3,4)‐connected supramolecular sheet with a point symbol of {3.4².5.6.7}₂{3.8²} by O–H ··· O hydrogen bonding interactions. The electrochemical behaviors of the two cobalt complexes 2 and 3 were reported. Moreover, the luminescent properties for 1 and the photocatalytic properties for the complexes were investigated.     

Synthesis,crystal structure and magnetic properties of (acetato‐κ2O,O′)bis(5,5′‐dimethyl‐2,2′‐bipyridine‐κ2N,N′)nickel(II) perchlorate monohydrate

The title hydrated ionic complex, [Ni(CH₃COO)(C₁₂H₁₂N₂)₂]ClO₄·H₂O or [Ni(ac)(5,5′‐dmbpy)₂]ClO₄·H₂O (where 5,5′‐dmbpy is 5,5′‐dimethyl‐2,2′‐bipyridine and ac is acetate), (1), was isolated as violet crystals from the aqueous ethanolic nickel acetate–5,5′‐dmbpy–KClO₄ system. Within the complex cation, the Ni^II atom is hexacoordinated by two chelating 5,5′‐dmbpy ligands and one chelating ac ligand. The mean Ni—N and Ni—O bond lengths are 2.0628 (17) and 2.1341 (15) Å, respectively. The water solvent molecule is disordered over two partially occupied positions and links two complex cations and two perchlorate anions into hydrogen‐bonded centrosymmetric dimers, which are further connected by π–π interactions. The magnetic properties of (1) at low temperatures are governed by the action of single‐ion anisotropy, D, which arises from the reduced local symmetry of the cis‐NiO₂N₄ chromophore. The fitting of the variable‐temperature magnetic data (2–300 K) gives g_iso = 2.134 and D/hc = 3.13 cm⁻¹.     

Synthesis,structure and magnetic properties of Ni2(NO3)4(APTY)4 (APTY=1,5-dimethyl-2-phenyl-4-{[(1 E )-pyridine-4-ylmethylene]amino}-1,2-dihydro-3 H -pyrazol-3-one)

A novel dinuclear nickel(II) complex Ni₂(NO₃)₄(APTY)₄ (1) (APTY?=?1,5-dimethyl-2-phenyl-4-{[(1E)-pyridine-4-ylmethylene]amino}-1,2-dihydro-3H-pyrazol-3-one), was synthesized by solvothermal reaction of Ni(NO₃)₂?·?6H₂O with APTY in methanol at 353?K. The structure consists of centrosymmetric dimers resulting from octahedrally coordinated Ni atoms bridged by APTY ligands. Weak intermolecular interactions (C–H?···?N, C–H?···?O hydrogen bonding, C–H?···?π and π–π stacking interactions) are responsible for a supramolecular assembly of molecules in the lattice. Magnetic measurements over 1.8–300?K show weak antiferromagnetic coupling between Ni(II) ions with J?=?2.969?cm^?1, g?=?2.280, θ?=??5.903.     

Syntheses,Structures, and Luminescence of Metal(II) Coordination Polymers based on Flexible 1,1′‐(1,4‐Butanediyl)bis(imidazole) and Tetrachlorobenzene‐1,4‐dicarboxylate Ligands

The coordination polymers, {[Co(bbim)₂(H₂O)₂](tcbdc) · 2H₂O}_n ( 1 ), {[Ni(tcbdc)(bbim)(H₂O)₂] · 2DMF}_n ( 2 ), and {[Cu₂(tcbdc)₂(bbim)₄] · 4H₂O}_n ( 3 ) [bbim = 1,1′‐(1,4‐butanediyl)bis(imidazole) and tcbdc^2– = tetrachlorobenzene‐1,4‐dicarboxylate] were synthesized and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis, luminescence, and single‐crystal X‐ray diffraction analysis. Complex 1 has a double‐stranded chain structure through doubly bridged [Co(bbim)₂] units. Complex 2 exhibits two‐dimensional square grid, whereas complex 3 has a three‐dimensional porous network structure with an unprecedented 4⁴ · 6¹¹ topological structure through interpenetrating square grid. The water molecules in complex 3 occupy the vacancy through three kinds of hydrogen bond interactions. Upon excitation at 370 nm, complexes 1 – 3 present solid‐state luminescence at room temperature.     

Synthesis,Characterization, and Magnetic Properties of Novel Cobalt(II) and Copper(II) Complexes with 5‐(Isonicotinamido)isophthalate Ligand

Two new complexes, {[Co(INAIP) · H₂O] · 2H₂O}_n ( 1 ), and {[Cu(INAIP)] · H₂O}_n ( 2 ) [H₂INAIP = 5‐(isonicotinamido)isophthalic acid] were synthesized under hydrothermal conditions, and characterized by single‐crystal X‐ray structure determination, thermogravimetric analysis, X‐ray powder diffraction, and magnetic studies. In complex 1 both Co^II atoms and INAIP^2– ligands act as four‐connected node, whereas in 2 both Cu^II atoms and INAIP^2– ligands act as three‐connected node.     

Mononuclear nickel(II) and zinc(II) complexes with deprotonated forms of the tripodal hexadentate ligand 1,3‐bis(2‐hydroxybenzylidene)‐2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methylpropane‐1,3‐diamine

In the crystal structures of both title compounds, [1,3‐bis(2‐hydroxybenzylidene)‐2‐methyl‐2‐(2‐oxidobenzylideneaminomethyl)propane‐1,3‐diamine]nickel(II) [2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methyl‐1,3‐bis(2‐oxidobenzylidene)propane‐1,3‐diamine]nickel(II) chloride methanol disolvate, [Ni(C₂₆H_25.5N₃O₃)]₂Cl·2CH₄O, and [1,3‐bis(2‐hydroxybenzylidene)‐2‐methyl‐2‐(2‐oxidobenzylideneaminomethyl)propane‐1,3‐diamine]zinc(II) perchlorate [2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methyl‐1,3‐bis(2‐oxidobenzylidene)propane‐1,3‐diamine]zinc(II) methanol trisolvate, [Zn(C₂₆H₂₅N₃O₃)]ClO₄·[Zn(C₂₆H₂₆N₃O₃)]·3CH₄O, the 3d metal ion is in an approximately octahedral environment composed of three facially coordinated imine N atoms and three phenol O atoms. The two mononuclear units are linked by three phenol–phenolate O—H...O hydrogen bonds to form a dimeric structure. In the Ni compound, the asymmetric unit consists of one mononuclear unit, one‐half of a chloride anion and a methanol solvent molecule. In the O—H...O hydrogen bonds, two H atoms are located near the centre of O...O and one H atom is disordered over two positions. The Ni^II compound is thus formulated as [Ni(H_1.5L)]₂Cl·2CH₃OH [H₃L is 1,3‐bis(2‐hydroxybenzylidene)‐2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methylpropane‐1,3‐diamine]. In the analogous Zn^II compound, the asymmetric unit consists of two crystallographically independent mononuclear units, one perchlorate anion and three methanol solvent molecules. The mode of hydrogen bonding connecting the two mononuclear units is slightly different, and the formula can be written as [Zn(H₂L)]ClO₄·[Zn(HL)]·3CH₃OH. In both compounds, each mononuclear unit is chiral with either a Δ or a Λ configuration because of the screw coordination arrangement of the achiral tripodal ligand around the 3d metal ion. In the dimeric structure, molecules with Δ–Δ and Λ–Λ pairs co‐exist in the crystal structure to form a racemic crystal. A notable difference is observed between the M—O(phenol) and M—O(phenolate) bond lengths, the former being longer than the latter. In addition, as the ionic radius of the metal ion decreases, the M—O and M—N bond distances decrease.