A binuclear CuII/CaII thiocyanate complex with a Schiff base ligand derived from o-vanillin and ammonia

The new heterometallic complex, aqua-1κO-bis(μ2-2-iminomethyl-6-methoxyphenolato-1κ2 O 1,O 6:2κ2 O 1,N)bis(thiocyanato-1κN)calcium(II)copper(II), [CaCu(C8H8NO2)2(NCS)2(H2O)], has been synthesized using a one-pot reaction of copper powder, calcium oxide, o-vanillin and ammonium thiocyanate in methanol under ambient conditions. The Schiff base ligand (C8H9NO2) is generated in situ from the condensation of o-vanillin and ammonia, which is released from the initial NH4SCN. The title compound consists of a discrete binuclear molecule with a {Cu(μ-O)2Ca} core, in which the Cu...Ca distance is 3.4275 (6) Å. The coordination geometries of the four-coordinate copper atom in the [CuN2O2] chromophore and the seven-coordinate calcium atom in the [CaO5N2] chromophore can be described as distorted square planar and pentagonal bipyramidal, respectively. In the crystal, O—H...S hydrogen bonds between the coordinating water molecules and thiocyanate groups form a supramolecular chain with a zigzag-shaped calcium skeleton.

A new structural motif for cadmium dithiocarbamates: crystal structures and Hirshfeld surface analyses of homoleptic zinc and cadmium morpholine dithiocarbamates

The crystal and molecular structures of two homoleptic morpholine-derived dithiocarbamates of zinc, binuclear {Zn[S2CN(CH2CH2)2O)2]2}2 (1), and cadmium, one-dimensional coordination polymer {Cd[S2CN(CH2CH2)2O)2]2}2 (2), are described. In 1, a centrosymmetric binuclear molecule is found as there are equal numbers of chelating and bidentate bridging dithiocarbamate ligands; weak transannular Zn···S interactions are found within the resultant eight-membered {···SCSZn}2 ring which has the form of a chair. The resultant 4+1 S5 donor set is highly distorted with the geometry tending towards a square-pyramid. By contrast, a square-planar geometry is found in centrosymmetric 2 defined by symmetrically chelating dithiocarbamate ligands. The presence of Cd···S secondary bonding in the crystal of 2 leads to a distorted 4+2 S6 octahedron and a linear coordination polymer, which is unprecedented in the structural chemistry of cadmium dithiocarbamates. The analyses of the Hirshfeld surfaces for 1 and 2 show the dominance of H···H, S···H/H···S and O···H/H···O contacts to the surface, i.e. contributing around 90 and 80%, respectively.

Steric control of supramolecular association in structures of Zn(S2COR)2 with N,N′-bis(pyridin-4-ylmethyl)oxalamide

The crystal and molecular structures of the one-dimensional coordination polymer [Zn(S2COEt)2(4LH2)]n (1) and binuclear [Zn(S2COCy)2]2(4LH2) (2) are described, where 4LH2 is N,N′-bis(pyridin-4-ylmethyl)ethanediamide. In 1, the Zn(S2COEt)2 entities are linked by bidentate bridging 4LH2 ligands through the pyridyl-N atoms to generate a twisted supramolecular chain. As a result of monodentate xanthate ligands, the N2S4 donor set defines a distorted tetrahedral coordination geometry and, crucially, allows the participation of the non-coordinating sulfur atoms in supramolecular association. Thus, in the crystal amide-N–H···O(amide) and amide-N–H···S(thione) hydrogen bonds link chains into a three-dimensional architecture. The substitution of the ethyl group in the xanthate ligand with a cyclohexyl group results in very different structural outcomes. In 2, a binuclear molecule is observed with the coordination geometry for zinc being defined by chelating xanthate ligands and a pyridyl-N atom with the NS4 donor set defining a highly distorted geometry. In the molecular packing, amide-N–H···S(thione) hydrogen bonds stabilise a supramolecular chain along the a-axis and these are connected into a three-dimensional arrangement by methylene-C–H···O and methylene-C–H···π(pyridyl) interactions. The relative importance of the specified intermolecular interactions and weaker, contributing contacts has been revealed by an analysis of the calculated Hirshfeld surfaces of 1 and 2.

(μ-Methylenediphosphonato-κ4 O,O′:O′′,O′′′)bis[(ethylenediamine-κ2 N,N′)palladium(II)] tetrahydrate

The title compound, [Pd2(C2H8N2)2(CH2O6P2)]·4H2O, comprises of a binuclear molecule (point group symmetry 2), with a twofold rotation axis running through the central C atom of the methylenediphosphonate (MDP) anion. The PdII atom has a square-planar coordination environment defined by the N atoms of a bidentate ethylenediamine (en) ligand and two O atoms of the bridging MDP anion. In the crystal structure, metal complexes are arranged in layers parallel (001) and are sandwiched between layers containing disordered water molecules of crystallization. Extensive intralayer hydrogen bonds of the type N—H...O in the metal complex layer and O—H...O in the water layer, as well as O—H...O hydrogen bonds between the two types of layers, lead to the formation a three-dimensional network structure. The two lattice water molecules are each equally disordered over two positions.

Crystal structure of the [(1,3-dimesityl-1H-imidazol-3-ium-2-yl)methanolato]copper(II) chloride dimer: insertion of formaldehyde into a copper–carbene bond

The crystal structure of bis[μ-(1,3-dimesityl-1H-imidazol-3-ium-2-yl)methanolato-κ2 O:O]bis[dichloridocopper(II)], [Cu2Cl4(C22H26N2O)2], is reported. The complex is assumed to have formed via the insertion of formaldehyde into the copper–carbon bond in an N-heterocyclic carbene complex of copper(I) chloride. The structure of the binuclear molecule possesses a crystallographically centrosymmetric Cu2O2 central core with the O atoms bridging between the CuII atoms and thus Z′ = 0.5. The copper centres are further ligated by two chloride ligands, resulting in the CuII atoms residing in a distorted square-planar environment. The Cu—O bond lengths are shorter than those previously reported in structures with the same central Cu2O2 motif. The complex displays C—H...Cl interactions involving the H atoms of the heterocycle backbone and the chloride ligands of a neighbouring molecule.

Crystal structures of di-μ-bromido-bis{dibromido[η5-2-(dimethylamino)indenyl]zirconium(IV)} and dibromidobis[η5-2-(dimethylamino)indenyl]zirconium(IV)

In the title compounds, [Zr2Br6(C11H12N)2], (I) and [ZrBr2(C11H12N)2], (II), the positions of the η5-binding 2-dimethylaminoindenyl units are fixed by intramolecular C—H...Br interactions involving aromatic or dimethylamino H atoms. The binuclear molecule of (I) is located on a general position, while the mononuclear molecule of (II) is situated on a twofold rotation axis. Both ZrIVatoms in (I) are ligated by one cyclopentadienyl (CP) ring and four Br ligands (two bridging, two terminal), while in (II) the ZrIVatom is ligated by two CP rings and two terminal Br ligands. The crystal structures of both (I) and (II) comprise of strands of π–π- and N–π-bonded molecules, which in turn are linked by C—H...Br interactions.

An unprecedented binuclear cadmium dithiocarbamate adduct: bis[μ2-N-(2-hydroxyethyl)-N-isopropylcarbamodithioato-κ3S:S,S′]bis{[N-(2-hydroxyethyl)-N-isopropylcarbamodithioato-κ2S,S′](3-{(1E)-[(E)-2-(pyridin-3-ylmethylidene)hydrazin-1-ylidene]methyl}pyridine-κN)cadmium]} dihydrate

The asymmetric unit in the title binuclear compound, [Cd(C6H12NOS2)2(C12H10N4)]2·2H2O, comprises a CdIIatom, two dithiocarbamate (dtc) anions, a monodentate 3-pyridinealdazine ligand and a lattice water molecule. The binuclear molecule is constructed by the application of inversion symmetry. One dtc ligand simultaneously chelates one cadmium atom and bridges the centrosymmetric mate, while the other dtc ligand is chelating only. This leads to a centrosymmetric [Cd(dtc)2]2core to which are appended two 3-pyridinealdazine ligands. The resulting NS5donor set is based on an octahedron. The three-dimensional molecular packing is sustained by hydroxyl-O—H(hydroxyl) and water-O—H...O(hydroxyl) hydrogen bonding, leading to supramolecular layers parallel to (101) which are connected by water-O—H...N(pyridyl) hydrogen bonding; additional C—H...O, S π(chelate ring) interactions are also evident. The retention of the central [Cd(dtc)2]2core upon adduct formation is unprecedented in the structural chemistry of the zinc-triad dithiocarbamates.

Crystal structure of Ag2(μ-SCN)2(NH3)4

Di-μ-thiocyanato-bis[diamminesilver(I)], [Ag2(μ-SCN)2(NH3)4], was synthesized by the reaction of AgSCN with anhydrous liquid ammonia. In the binuclear molecule, the AgIatom is coordinated by two ammine ligands and the S atom of one thiocyanate ligand. Two of these [Ag(SCN)(NH3)2] units are bridged by the S atoms of the thiocyanate anions at longer distances, leading to a dimer with point group symmetryC2. The distance between the AgIatoms in the dimer is at 3.0927 (6) Å within the range of argentophilic interactions. The crystal structure displays N—H...N and N—H...S hydrogen-bonding interactions that build up a three-dimensional network.

Crystal structure of bis(μ-2-benzoylbenzoato-κ2O:O′)bis[bis(2,2′-bipyridine-κ2N,N′)manganese(II)] bis(perchlorate)

The title compound, [Mn2(C6H5COC6H4COO)2(C10H8N2)4](ClO4)2, comprises a centrosymmetric binuclear cation and two perchlorate anions. In the complex cation, two MnIIatoms are bridged by two O atoms of two different 2-benzoylbenzoate ligands, each MnIIatom being further coordinated by two 2,2′-bipyridine (bipy) ligands in a distorted octahedral environment. Within the binuclear molecule, the Mn...Mn separation is 4.513 (7) Å. Intermolecular C—H...O and C—H... π interactions link the molecules into a three-dimensional network.

Synthesis and crystal structures of two coordination polymers and a binuclear cadmium(II) complex containing 3- and 4-aminobenzoate ligands

Due to their wide range of coordination modes and versatile conformations when binding to metal atoms, multicarboxylate ligands are of interest in the design of metal–organic frameworks (MOFs). Three CdIIcomplexes, namelycatena-poly[diammonium [[chloridocadmium(II)]-di-μ-chlorido-[chloridocadmium(II)]-bis(μ-3-aminobenzoato)-κ3N:O,O′;κ3O,O′:N]], {(NH4)[CdCl2(C7H6NO2)]}n, (I),catena-poly[[[aquacadmium(II)]-bis(μ-4-aminobenzoato)-κ3N:O,O′;κ3O,O′:N] monohydrate], {[Cd(C7H6NO2)2(H2O)]·H2O}n, (II), and di-μ-acetato-κ4O:O′-bis[(4-aminobenzoato-κ2O,O′)(2,2′-bipyridine-κ2N,N′)cadmium(II)], [Cd2(CH3COO)2(C7H6NO2)2(C10H8N2)2], (III), with different stuctural forms are reported. Complex (I) has a one-dimensional ladder structure, with strong N—H...O and weak N—H...Cl hydrogen bonds linking the cations and anions in the three-dimensional supramolecular structure. Complex (II) has a one-dimensional chain structure. Extensive O—H...O and N—H...O hydrogen bonds between the anionic ligands and the solvent water molecules and π–π stacking interactions between the centroids of the benzene rings lead to the three-dimensional supramolecular structure. Complex (III) is a binuclear molecule which is extended into a three-dimensional supramolecular structureviastrong N—H...O and weak C—H...O hydrogen bonds.