(Glycylglycinato‐κ3O,N,N′)(2‐methyl‐1H‐benzimidazole‐κN3)copper(II) trihydrate

In the title compound, [Cu(C₄H₆N₂O₃)(C₈H₈N₂)]·3H₂O, the Cu^II atom is coordinated in a square‐planar manner by one O atom and three N atoms from glycylglycinate and 2‐methyl­benzimidazole ligands. The ternary complexes assemble into one‐dimensional chains through C—H⋯π inter­actions and direct N—H⋯O hydrogen bonding, as well as into hydrogen‐bonded water helices with branches which also link the complex chains into a three‐dimensional supra­molecular structure.     

Dichloro­(O‐ethyl 3‐methyl­pyridine‐2‐carboximidic acid‐κ2N,N′)copper(II)

In the title compound, [CuCl₂(C₉H₁₂N₂O)], the Cu^II atom is coordinated by two Cl⁻ anions and two N atoms of one O‐ethyl 3‐methyl­pyridine‐2‐carboximidic acid mol­ecule in a slightly distorted square‐planar geometry, with Cu—N distances of 2.0483 (17) and 1.9404 (18) Å, and Cu—Cl distances of 2.2805 (10) and 2.2275 (14) Å. In addition, each Cu^II atom is connected by one Cl⁻ anion and the Cu^II atom from a neighbouring mol­ecule, with Cu⋯Cl and Cu⋯Cu distances of 2.9098 (13) and 3.4022 (12) Å, respectively, and, therefore, a centrosymmetric dimer is formed. Adjacent mol­ecular dimers are connected by π–π stacking inter­actions between pyridine rings to form a zigzag mol­ecular chain. The mol­ecular chains are also enforced by N—H⋯Cl and C—H⋯Cl inter­actions.     

(2,2′‐Di­amino‐4,4′‐bi‐1,3‐thia­zole‐κ2N3,N3′)(oxy­diacetato‐κ3O,O′,O′′)­copper(II) monohydrate

The title compound, [Cu(C₄H₄O₅)(C₆H₆N₄S₂)]·H₂O, displays a square‐pyramidal coordination geometry. The tridentate oxy­di­acetate dianion chelates the Cu^II atom in the facial mode. The large difference [0.487 (4) Å] between the longest Cu—O distance in the basal plane and that in the apical direction correlates with the small displacement of the Cu^II atom [0.0576 (13) Å] from the basal plane towards the apex of the square pyramid. The intermolecular hydrogen‐bonding network results in a closely overlapped arrangement of the coordination basal plane and the thia­zole ring of a neighboring mol­ecule.     

catena‐Poly[[[diaqua­bis(pyridine‐4‐carboxamide‐κN)copper(II)]‐μ2‐squarato‐κO1:O3] dihydrate]

The asymmetric unit of the title compound, {[Cu(C₄O₄)(C₆H₆N₂O)₂(H₂O)₂]·2H₂O}_n, consists of one pyridine‐4‐carbox­amide (isonicotinamide or ina) ligand, one‐half of a squarate dianion, a coordinated aqua ligand and a solvent water mol­ecule. Both the Cu^II and the squarate ions are located on inversion centers. The Cu^II ions are octa­hedrally surrounded by four O atoms of two water mol­ecules and two squarate anions, and by two N atoms of the isonicotinamide ligands. The crystal structure contains chains of squarate‐1,3‐bridged Cu^II ions. These chains are held together by N—H⋯O and O—H⋯O inter­molecular hydrogen‐bond inter­actions, forming an extensive three‐dimensional network.     

Poly­[[di­aqua­cobalt(II)]‐μ‐4,4′‐bi­pyridine‐κ2N:N′‐μ‐p‐phenyl­enebis­(oxy­acetato)‐κ2O:O′]

The title compound, [Co^II(C₁₀H₈O₆)(C₁₀H₈N₂)(H₂O)₂]_n, was obtained by the hydro­thermal reaction of CoSO₄ with benzene‐1,4‐dioxy­di­acetate [systematic name: p‐phenyl­ene­bis­(oxy­acetate)] and 4,4′‐bi­pyridine (4,4′‐bpy). The Co atom lies at an inversion center and the benzene‐1,4‐dioxydiacetate and 4,4′‐bipyridine moieties lie about other inversion centers. The benzene‐1,4‐dioxydiacetate ligands bridge the octahedral Co^II coordination centers, forming a one‐dimensional zigzag chain. The chains are further bridged by 4,4′‐bpy ligands, forming a novel two‐dimensional supramolecular architecture. Hydro­gen‐bonding interactions between the coordinated water mol­ecules and the carboxyl­ate O atoms lead to the formation of a three‐dimensional network structure.     

(2‐Aminopyrimidine‐κN1)aqua(pyridine‐2,6‐dicarboxylato‐κ3O2,N,O6)copper(II): X‐ray and DFT calculated structure

In the title compound, [Cu(C₇H₃N₂O₄)(C₄H₅N₂)(H₂O)], (I), pyridine‐2,6‐dicarboxylate (pydc²⁻), 2‐aminopyrimidine and aqua ligands coordinate the Cu^II centre through two N atoms, two carboxylate O atoms and one water O atom, respectively, to give a nominally distorted square‐pyramidal coordination geometry, a common arrangement for copper complexes containing the pydc²⁻ ligand. Because of the presence of Cu...X_bridged contacts (X = N or O) between adjacent molecules in the crystal structures of (I) and three analogous previously reported compounds, and the corresponding uncertainty about the effective coordination number of the Cu^II centre, density functional theory (DFT) calculations were used to elucidate the degree of covalency in these contacts. The calculated Wiberg and Mayer bond‐order indices reveal that the Cu...O contact can be considered as a coordination bond, whereas the amine group forming a Cu...N contact is not an effective participant in the coordination environment.     

catena‐Poly[[bis(1H‐benzimidazole‐κN3)(salicylato‐κO)copper(II)]‐μ‐salicylato‐O,O′:O′′]

The title compound, [Cu(C₇H₅O₃)₂(C₇H₆N₂)₂]_n, is a one‐dimensional polymeric complex bridged by salicyl­ate anions. The Cu^II atom is surrounded by three salicyl­ate and two benz­imidazole ligands, with a tetragonally elongated octahedral coordination geometry. The Cu—O bond distances in the axial directions are 2.6092 (16) and 2.6834 (17) Å. π–π stacking interactions exist between the benz­imidazole rings of neighboring polymeric complex chains.     

catena‐Poly[[dicyanamido(5,5′‐dimethyl‐2,2′‐bipyridine‐κ2N,N′)copper(II)]‐μ‐dicyanamido‐κ2N1:N5]

In the crystal structure of the title compound, [Cu(C₂N₃)₂(C₁₂H₁₂N₂)]_n, the Cu^II atom adopts a distorted square‐pyramidal geometry, the basal plane of which is formed by two N atoms of the bi­pyridine ligand, one N atom of a bidentate dicyan­amide anion and one N atom of a monodentate dicyan­amide anion [Cu—N = 1.9760 (15)–2.0157 (15) Å]. The apical position is occupied by an N atom of a bidentate dicyan­amide anion, located 2.2468 (16) Å from the Cu atom, thus forming a one‐dimensional polymeric chain.     

Tetrakis(2,2′‐bipyridine‐κ2N,N′)­tetrakis(μ‐salicyl­ato‐κ3O,O′:O′′)‐quadro‐tetrazinc(II) decahydrate

The title compound, [Zn₄(C₇H₄O₃)₄(C₁₀H₈N₂)₄]·10H₂O, crystallizes as a centrosymmetric tetranuclear cyclic complex containing four Zn^II atoms bridged by four carboxyl­ate groups from salicyl­ate ligands, with a syn–anti configuration. Each Zn^II atom has a distorted trigonal–bipyramidal coordination geometry, formed by two N atoms of a 2,2′‐bipyridine ligand and three O atoms from two salicyl­ate ligands. The complex is stabilized by intramolecular π–π interactions between pairs of bi­pyridine rings and a 16‐membered gear‐wheel‐shaped cyclic framework. The hydrogen‐bonding network is formed via the water mol­ecules.     

Diaqua(oxydiacetato‐κ3O,O′,O′′)(pyridine‐3‐carboxamide‐κN1)copper(II)

In the mononuclear title compound, [Cu(C₄H₄O₅)(C₆H₆N₂O)(H₂O)₂], the Cu^II centre is bound to a chelating oxydiacetate ligand, a monodentate pyridine‐3‐carboxamide unit and two water molecules, defining an octahedral coordination where the first two ligands form the equatorial plane and the last two occupy the apical sites. The planar oxydiacetate ligand is slightly disordered at its central ether O atom. The availability of efficient donors and acceptors for hydrogen bonding results in a complex interaction scheme where each monomer links to six similar units to define a well connected three‐dimensional structure. A comparison is made with related structures in the literature, and the reasons for their differences are discussed.     

Aqua(oxydiacetato‐κ3O,O′,O′′)(pyridine‐3‐carboxamide‐κN1)copper(II) sesquihydrate

In the monomeric title compound, [Cu(C₄H₄O₅)(C₆H₆N₂O)(H₂O)]·1.5H₂O, the Cu^II cation is bound in a square‐pyramidal coordination to a tridentate oxydiacetate (ODA) ligand, a monodentate pyridine‐3‐carboxamide (p3ca) ligand and one aqua ligand, where the two organic ligands form the basal plane and the water O atom occupies the unique apical site. The ODA ligand presents a slight out‐of‐plane puckering in its central ether O atom, while the p3ca ligand is essentially planar. The availability of efficient donors and acceptors for hydrogen bonding results in the formation of strongly linked hydrogen‐bonded bilayers parallel to (101), with an interplanar distance of 3.18 (1) Å and a stacking separation between the bilayers of 3.10 (1) Å, both of them governed by extended π–π interactions. The disordered nature of the solvent water molecules around inversion centres is discussed. The monoaqua compound is compared with the octahedral diaqua analogue, [Cu(C₄H₄O₅)(C₆H₆N₂O)(H₂O)₂], reported recently [Perec & Baggio (2009). Acta Cryst. C 65 , m296–m298].     

Bis(acesulfamato‐κ2O4,N)bis­(3‐methyl­pyridine)copper(II)

In the crystal structure of the title compound {systematic name: bis­[6‐methyl‐1,2,3‐oxa­thia­zin‐4(3H)‐one 2,2‐dioxide(1−)‐κ²N³,O⁴]bis­(3‐meth­yl­pyridine)copper(II)}, [Cu(C₄H₄NO₄S)₂(C₆H₇N)₂], the Cu^II centre resides on a centre of symmetry and has an octa­hedral geometry that is distorted both by the presence of four‐membered chelate rings and because of the Jahn–Teller effect. The equatorial plane is formed by the N atoms of two methyl­pyridine ligands and by the more basic O atoms of the acesulfamate ligands, while the weakly basic N atoms of these ligands are in elongated axial positions with a misdirected valence. The crystal is stabilized by two inter­molecular C—H⋯O inter­actions involving the methyl and CH groups, and the sulfonyl O atoms of the acesulfamate group.     

Aqua­(2,2′‐diamino‐4,4′‐bi‐1,3‐thia­zole‐κ2N,N′)(oxydiacetato‐κ3O,O′,O′′)cobalt(II) trihydrate

The title compound, [Co(C₄H₄O₅)(C₆H₆N₄S₂)(H₂O)]·3H₂O, displays a distorted octa­hedral coordination geometry. The tridentate oxydiacetate dianion chelates the Cu^II atom in the meridional mode. In the crystal packing, hydro­philic and hydro­phobic layers are arranged in an alternating manner. In addition, a three‐dimensional hydrogen‐bonding framework and π–π stacking are present.     

Poly[[aqua­copper(II)]‐μ‐adamantane‐1,3‐diacetato]

In the title compound, [Cu(C₁₄H₁₈O₄)(H₂O)]_n, each Cu^II atom bonds to four O atoms of four adamantanediacetate (ada) ligands in equatorial positions and an O atom from a water mol­ecule in the apical position. Two adjacent Cu^II atoms form a paddle‐wheel unit with four ada ligands. The distance between the two Cu atoms is 2.5977 (3) Å. A crystallographic inversion center is located at the center of the Cu–Cu core. Each Cu₂(ada)₄ paddle‐wheel further bonds to four adjacent identical paddle‐wheel units, generating a two‐dimensional layered structure of Cu(ada)(H₂O) with a 4⁴ topology.     

catena‐Poly[[(1,10‐phenanthroline‐κ2N,N′)copper(II)]‐μ‐(dihydrogen benzene‐1,2,4,5‐tetracarboxylato)‐κ2O1:O4]

In the title compound, [Cu(C₁₀H₄O₈)(C₁₂H₈N₂)]_n, the Cu^II cation has a four‐coordination environment completed by two N atoms from one 1,10‐phenanthroline (phen) ligand and two O atoms belonging to two di­hydrogen benzene‐1,2,4,5‐­tetra­carboxyl­ate anions (H₂TCB²⁻). There is a twofold axis passing through the Cu^II cation and the centre of the phen ligand. The [Cu(phen)]²⁺ moieties are bridged by H₂TCB²⁻ anions to form an infinite one‐dimensional coordination polymer with a zigzag chain structure along the c axis. A double‐chain structure is formed by hydrogen bonds between adjacent zigzag chains. Furthermore, there are π–π stacking inter­actions between the phen ligands, with an average distance of 3.64 Å, resulting in a two‐dimensional network structure.     

{μ‐N,N′‐Bis[3‐(dimethyl­amino)prop­yl]­oxamidato(2–)‐κ6N,N′,O′:N′′,N′′′,O}­bis­[(1H‐imidazole‐κN3)(methanol‐κO)copper(II)] bis­(perchlorate)

The structure of the title compound, [Cu₂(C₁₂H₂₄N₄O₂)(C₃H₄N₂)₂(CH₄O)₂](ClO₄)₂ or [Cu₂(dmoxpn)(HIm)₂(CH₃OH)₂](ClO₄)₂, where dmoxpn is the dianion of N,N′‐bis­[3‐(dimethyl­amino)prop­yl]oxamide and HIm is imidazole, consists of a centrosymmetric trans‐oxamidate‐bridged copper(II) binuclear cation, having an inversion centre at the mid‐point of the central C—C bond, and two perchlorate anions. The Cu^II atom has square‐pyramidal coordination geometry involving two N atoms and an O atom from the dmoxpn ligand, an N atom from an imidazole ring, and an O atom from a methanol mol­ecule. The crystal structure is stabilized by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds and imidazole π–π stacking inter­actions to form a three‐dimensional supra­molecular array.     

Bis(1,10‐phenanthroline‐κ2N,N′)(squarato‐κO)copper(II) trihydrate

The title mononuclear [Cu(sq)(phen)₂]·3H₂O complex [sq is squarate (C₄O₄) and phen is 1,10‐phenanthroline (C₁₂H₈N₂)] has been synthesized and the structure consists of a neutral mononuclear [Cu(sq)(phen)₂] unit and three solvate water mol­ecules. The Cu^II ion has distorted square‐pyramidal coordination geometry, comprised of one carboxyl­ate O atom from a monodentate squarate ligand and four N atoms from two chelating phen ligands. An extensive three‐dimensional network of OW—H⋯O/OW hydrogen bonds, face‐to‐face π–­π interactions between the 1,10‐phenanthroline aromatic rings and a weak π–ring interaction are responsible for crystal stabilization.     

Bis(2,2′‐bipyridine)(dicyanamido)­copper(II) tetrafluoroborate

In the title compound, [Cu(C₂N₃)(C₁₀H₈N₂)₂]BF₄, the Cu^II atom shows distorted trigonal‐bipyramidal geometry, with the dicyan­amido ligand in the equatorial plane. The two out‐of‐plane Cu—N bond lengths to bi­pyridine are 2.006 (3) and 1.998 (3) Å, whereas the in‐plane Cu—N distances are 2.142 (3) and 2.043 (3) Å to the bi­pyridine, and 2.015 (3) Å to the dicyan­amide.     

(Croconato‐κ2O,O′)bis­(1,10‐phenanthroline‐κ2N,N′)cobalt(II), and the nickel(II) and copper(II) analogues

The title complexes, [M(C₅O₅)(C₁₂H₈N₂)₂], with M = Co^II, Ni^II and Cu^II, all lie across twofold rotation axes, around which two 1,10‐phenanthroline ligands are arranged in a chiral propeller manner. The Co^II and Ni^II complexes are isostructural, with octa­hedral coordination geometry, while the local geometry of the Cu^II complex is severely distorted from octa­hedral.     

μ‐Acetato‐1:2κ2O:O′‐diacetato‐1κ2O,O′;2κO‐bis(di‐2‐pyridylamine)‐1κ2N,N′;2κ2N,N′‐isothiocyanato‐2κN‐dicopper(II)

In the title dinuclear acetate‐bridged complex, [Cu₂(C₂H₃O₂)₃(NCS)(C₁₀H₉N₃)₂], the two Cu atoms are five‐coordinated, with a basal plane consisting of two N atoms of a di‐2‐pyridylamine (dpyam) ligand and two O atoms of two different acetate ligands. The axial positions of these Cu atoms are coordinated to N and O atoms from thio­cyanate and acetate mol­ecules, respectively, leading to a distorted square‐pyramidal geometry with τ values of 0.30 and 0.22. Both Cu^II ions are linked by an acetate group in the equatorial–equatorial positions and have syn–anti bridging configurations. Hydrogen‐bond inter­actions between the amine H atom and the coordinated and uncoordinated O atoms of the acetate anions generate an infinite one‐dimensional chain.