Bis(μ‐ethyl pyridine‐2,6‐di­carboxyl­ato)­bis­[di­aqua­chloro­cadmium(II)] dihydrate

The reaction of cadmium chloride with pyridine‐2,6‐di­carboxylic acid (PDA) and 98% H₂SO₄ in ethanol led to the formation of the title compound, bis­[μ‐6‐(ethoxy­carbonyl)­pyridine‐2‐carboxyl­ato]‐1:2κ⁴O⁶,N,O²:O²;1:2κ⁴O²:O²,N,O⁶‐bis­[di­aqua­chloro­cadmium(II)] dihydrate, [Cd₂(C₉H₈NO₄)₂Cl₂(H₂O)₄]·2H₂O. PDA is esterified to monoethyl ­pyridine‐2,6‐di­carboxyl­ate (MEPD) by the catalysis of H₂SO₄ during the reaction. The dinuclear Cd^II complex lies about an inversion centre and the unique Cd atom has a pentagonal–bipyramidal geometry. The two Cd atoms are bridged by two carboxyl­ate O atoms, forming a planar Cd₂O₂ unit. Stair‐like chains are formed via O—H⋯Cl hydrogen bonds and these are further arranged into two‐dimensional layers via hydrogen bonds involving solvate water mol­ecules.     

Bis(μ‐pyridine‐2,6‐carboxyl­ato‐O,N,O′:O)­bis­[tri­aqua­manganese(II)]–pyridine‐2,6‐di­carboxylic acid (1/2)

In the structure of the title compound, [Mn₂(C₇H₃NO₄)₂(H₂O)₆]·2C₇H₅NO₄, a centrosymmetric dinuclear complex, hexaa­aqua­bis­(pyri­dine‐2,6‐di­carboxyl­ato)­dimanganese(II) and free pyri­dine‐2,6‐di­carboxyl­ic acid are present in a 1:2 ratio. In the complex, each Mn²⁺ ion is coordinated by three O atoms and one N atom from the pyridine‐2,6‐di­carboxyl­ate ligands and by three water O atoms, resulting in a distorted pentagonal bipyramidal coordination. Within the centrosymmetric dinuclear complex, two Mn²⁺ ions are bridged by two carboxyl­ate O atoms. The crystal structure is stabilized by hydrogen bonds involving all the H atoms of the water ligands.     

An indium(III)–water chain based on an unusual acyclic water pentamer

An in situ reaction under hydro­thermal conditions leads to the formation of the title compound, diaqua­(pyridine‐2‐carboxyl­ato)­(pyridine‐2,6‐dicarboxyl­ato)indium(II) trihydrate, [In(C₆H₄NO₂)(C₇H₃NO₄)(H₂O)₂]·3H₂O, in which the central In^III atom is seven‐coordinated by one pyridine‐2,6‐di­carboxyl­ate ligand, one pyridine‐2‐carboxyl­ate ligand and two water mol­ecules in a penta­gonal–bipyramidal coordination environment. An indium(III)–water chain based on an unusual water pentamer is observed.     

The sodium salt of a tris­(tridentate anion)­gadolinium(III) complex: penta­sodium bis­[chelidamato(3−)][chelidamato(2−)]­gadolinate(III) hexa­deca­hydrate

The sodium salt of a complex anion formed between gadolinium(III) and three variously deprotonated chelidamic acid (4‐hydroxy­pyridine‐2,6‐di­carboxyl­ic acid) ligand moi­eties, assigned as Na₅[Gd(C₇H₂NO₅)₂(C₇H₃NO₅)]·16H₂O, i.e. pentasodium (4‐hydroxy­pyridine‐2,6‐di­carboxyl­ate)­bis(4‐oxido­pyridine‐2,6‐di­carboxyl­ate)­gadolinium(III) hexadecahydrate, forms as colourless monoclinic crystals upon vapour diffusion of ethanol into its aqueous solution. The ligand moieties, assigned as two trianionic and one dianionic chelidamate species, are all tridentate in the complex anion of tricapped trigonal prismatic donor‐atom geometry. The geometry of the ligands and that of the primary coordination sphere is very similar to that of the analogous anionic tris­(ligand)–rare earth complexes of the pyridine‐2,6‐di­carboxyl­ate (dipicolinate) dianion.     

Tetrakis(μ‐2,3‐dimethoxybenzoato)bis[(2,2′‐bipyridine)(2,3‐dimethoxybenzoato)lanthanum(III)]

The title compound, tetrakis(μ‐2,3‐di­methoxy­benzoato)‐κ⁴O:O′;κ⁶O,O′:O′‐bis[(2,2′‐bi­pyridine‐N,N′)(2,3‐di­methoxy­benzoato‐O,O′)lanthanum(III)], [La₂(2,3‐DMOBA)₆(2,2′‐bpy)₂], where 2,3‐DMOBA is 2,3‐di­methoxy­benzoate (C₉H₉O₄) and 2,2′‐bpy is 2,2′‐bi­pyridine (C₁₀H₈N₂), is a dimer with a centre of inversion between the La atoms bridged by four carboxyl­ate ligands. The central La atom is ennea‐coordinated and has a distorted monocapped square‐antiprism geometry.     

trans‐(2‐Acetylpyridine‐κ2N,O)dichlorobis(dimethyl sulfoxide‐κS)ruthenium(II)

In the title complex, [RuCl₂(C₇H₇NO)(C₂H₆OS)₂], the metal ion is at the centre of a distorted octahedral NOCl₂S₂ coordination sphere. The neutral 2‐acetyl­pyridine ligand binds to the metal ion through the pyridine N and carbonyl O atoms, forming a five‐membered chelate ring. The monodentate S‐coordinating di­methyl sulfoxide mol­ecules are mutually cis, and the two remaining positions in the coordination sphere are occupied by two mutually trans Cl^? ions.     

Dicarbonyldi‐μ‐chloro‐cis,cis‐η4‐1,5‐cyclo­octa­dienedirhodium(I)

The title compound, dicarbonyl‐1κ²C‐di‐μ‐chloro‐1:2κ⁴Cl‐[cis,cis‐2(η⁴)‐1,5‐cyclo­octa­diene]­di­rhodium(I), [Rh₂Cl₂(C₈H₁₂)(CO)₂], consists of a di­chloro‐bridged dimer of rhodium, with a non‐bonded Rh?Rh distance of 3.284 (2) Å. One Rh atom is coordinated to two carbonyl ligands, while the other Rh atom is coordinated to the cyclo­octa­diene moiety.     

A one‐dimensional ladder‐like coordination polymer derived from chains formed via hydrogen bonds: catena‐poly­[[aqua­di­pyridine­nickel(II)]‐μ‐2,2′‐di­thio­dibenzoato‐κ3O,O′:O′′]

The title one‐dimensional chain nickel(II)–di­sulfide complex, [Ni(C₁₄H₈O₄S₂)(C₅H₅N)₂(H₂O)]_n, has each Ni^II cation coordinated by two N atoms from two pyridine ligands, three carboxyl­ate O atoms from two different di­thio­dibenzoate ligands and one O atom from a coordinated water mol­ecule, in a distorted octahedral coordination geometry. Each di­thio­dibenzoate ion links two Ni^II cations through its carboxyl­ate O atoms, making the structure polymeric. Hydro­gen‐bond interactions between two shoulder‐to‐shoulder chains lead to the formation of a ladder‐like structure.     

Three methoxy‐substituted diethyl 4‐­phenyl‐2,6‐di­methyl‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate compounds

Diethyl 4‐(2,5‐di­methoxy­phenyl)‐2,6‐di­methyl‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate, C₂₁H₂₇NO₆, (I), diethyl 4‐(3,4‐di­methoxy­phenyl)‐2,6‐di­methyl‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate, C₂₁H₂₇NO₆, (II), and diethyl 2,6‐di­methyl‐4‐(3,4,5‐tri­methoxy­phenyl)‐1,4‐di­hydro­pyridine‐3,5‐di­carboxyl­ate, C₂₂H₂₉NO₇, (III), crystallize with hydrogen‐bonding networks involving the H atom bonded to the N atom of the 1,4‐di­hydro­pyridine ring and carbonyl O atoms in (I) and (II). Unusually, (III) shows O atoms of methoxy groups serving as hydrogen‐bond acceptors.     

cis‐Di­chloro(5,8‐dioxa‐2,11‐dithia[12]‐o‐cyclo­phane)­palladium(II)

The preparation and crystal structure of the title compound, cis‐di­chloro­[6,9‐dioxa‐3,12‐di­thia­bi­cyclo­[12.4.0]­octadeca‐14,‐16,­18(1)‐tri­ene‐S,S′]­palladium(II), [PdCl₂(C₁₄H₂₀O₂S₂)], are described. The Pd atom has a square‐planar environment, coordinated to two S atoms of the di­thia­dioxa macrocycle and to two Cl^? ions. The non‐coordinating O atoms are oriented away from the metal coordination plane. Upon complexation, a bicyclic chelate structure, which consists of a seven‐ and an eleven‐membered ring, is formed.     

trans‐Bis­[ethane‐1,2‐di­thiol­ato(2–)‐S,S′]­bis(2‐mer­cap­to­pyri­dine‐S)­tin(IV)

The title compound, [Sn(C₅H₅NS)₂(C₂H₄S₂)₂], was obtained from a 1:2 mixture of bis­(ethane‐1,2‐di­thiol­ato)­tin(IV) and 2‐mercapto­pyridine. The mol­ecules are discrete monomeric trans‐octahedral units, with the Sn^IV atom at the centre of symmetry, planar 2‐mercapto­pyridine zwitterions and SnS₂C₂ groups in twist–envelope conformations. The 2‐mercapto­pyridine ligands are monodentate and are bonded through the S atoms. The S—Sn distances between the S atom of edt (edt is ethane‐1,2‐di­thiol­ate) and the Sn atom are 2.473 (1) and 2.505 (1) Å, which are slightly longer than the S—Sn distance in Sn(edt)₂ of 2.390 (1) Å. The bond between the 2‐mercapto­pyridine S atom and the Sn atom are, remarkably, weaker than the S—Sn bond involving edt.     

A host–guest complex of di­aqua­bis­[1‐hydroxy‐2(1H)‐pyridine­thionato‐O,S]­magnesium(II) and 2,2′‐di­thio­bis­(pyridine N‐oxide)

The title compound, [Mg(C₅H₄NOS)₂(H₂O)₂]·C₁₀H₈N₂O₂S₂, is a two‐component host–guest material. The 2,2′‐di­thio­bis(pyridine N‐oxide) molecule has crystallographic twofold symmetry. The metal complex lies on an inversion centre and associates via C—H?S interactions into chains which thread the 2,2′‐di­thio­bis­(pyridine N‐oxide) lattice in perpendicular directions. Hydro­gen bonds exist between the water mol­ecules of the di­aqua­magnesium units and the N—O groups of the host lattice.     

Complexes of di­methyl­tin dihalides with N‐methyl­pyrrolidinone,C12H24N2O2X2Sn (X = Cl,Br or I)

The single‐crystal X‐ray structure determinations of the title complexes, cis‐di­chloro‐trans‐di­methyl‐cis‐bis(N‐methyl­pyr­rolidin‐2‐one‐O)­tin(IV), [Sn(CH₃)₂Cl₂(C₅H₉NO)₂], cis‐di­bromo‐trans‐di­methyl‐cis‐bis(N‐methyl­pyrrolidin‐2‐one‐O)tin­(IV), [SnBr₂(CH₃)₂(C₅H₉NO)₂], and cis‐di­iodo‐trans‐di­methyl‐cis‐bis(N‐methyl­pyrrolidin‐2‐one‐O)­tin(IV), [Sn(CH₃)₂I₂(C₅H₉NO)₂], show that those tin complexes in which coordination of the lactam ligand to Sn^IV is realized via oxygen exhibit a distorted octahedral geometry.     

A chloride ion contained in a cobalt `claw': [Co3(DADIT)3]Cl(PF6)2

A trimeric compound containing Co^II is described, namely tris{μ‐2‐[3‐(di­methyl­amino)­propyl­imino]­propane‐1‐thiol­ato}­tricobalt(II) chloride bis­(hexa­fluoro­phosphate), [Co₃(C₁₀H₂₁N₂S)₃]Cl(PF₆)₂. Each Co atom is ligated by one 2‐[3‐(di­methyl­amino)­propyl­imino]­propane‐1‐thiol­ate ligand, an am­ine group and an imine group. The thiol­ate groups bridge the Co atoms, forming a six‐membered ring that encloses the chloride ion in a well defined binding pocket.     

Di­cyclo­hexyl­ammonium 2,4‐di­chloro­phenoxy­acetate and (2,4‐di­chloro­phenoxy­acetato‐O,O′)bis­(tri­phenylphosphine‐P)silver(I)

The monoclinic cell of di­cyclo­hexyl­ammonium 2,4‐di­chloro­phenoxy­acetate contains four C₁₂H₂₄N⁺·C₅H₈Cl₂O₃^? ion pairs. The ammonium N atom is hydrogen bonded to the oxy­gen ends of two carboxyl groups to form a 12‐membered O—C—O?HNH?O—C—O?HNH ring. In (2,4‐di­chloro­phenoxy­lacetato)­bis­(tri­phenyl­phosphine)silver(I), [Ag(C₈H₅Cl₂O₃)(C₁₈H₁₅P)₂], the carboxyl CO₂ unit chelates to the Ag atom in an anisobidentate manner [Ag—O = 2.436 (2) and 2.517 (2) Å]; the Ag atom shows distorted tetrahedral geometry.     

cis‐[1,4‐Bis(di­phenyl­phosphino)­butane](μ‐tetra­thio­tungstato)­palladium(II) N,N′‐di­methyl­form­amide hemisolvate hemihydrate

In the title compound, [1,4‐bis(di­phenyl­phosphino)­butane‐2κ²P,P′]­di‐μ‐thio‐1:2κ⁴S‐di­thio‐1κ²S‐palladium(II)­tung­sten(VI) N,N′‐di­methyl­form­amide hemisolvate hemihydrate, [PdWS₄­(C₂₈H₂₈P₂)]·0.5C₃H₇NO·0.5H₂O, the Pd atom is coordinated by two S atoms from the distorted‐tetrahedral [WS₄]²⁻ anion and two P atoms from the dppb mol­ecule [dppb is 1,4‐bis(di­phenyl­phos­phino)­butane] in an approximately square‐planar configuration. A puckered seven‐membered ring is formed by the Pd atom and the dppb ligand.     

Two isomorphous imidazole (Him) complexes: [MCl2(Him)2(H2O)2] (M = Co and Ni)

The structures of aqua­di­chloro­bis(1H‐imidazole)­cobalt(II), [CoCl₂(Him)₂(H₂O)₂] (Him is 1H‐imidazole, C₃H₄N₂), (I), and aqua­di­chloro­bis(1H‐imidazole)­nickel(II), [NiCl₂(Him)₂(H₂O)₂], (II), are isomorphous and consist of monomers with inversion symmetry. The three monodentate ligands (imidazole, chlorine and aqua), together with their symmetry equivalents, define almost perfect octahedra. Hydro­gen‐bonding interactions via the imidazole and aqua H atoms lead to a three‐dimensional network.     

RbCrIII(C2O4)2·2H2O,Cs2Mg(C2O4)2·4H2O and Rb2CuII(C2O4)2·2H2O: three new complex oxalate hydrates

Rubidium chromium(III) dioxalate dihydrate [di­aqua­bis(μ‐oxalato)­chromium(III)­rubidium(I)], [RbCr(C₂O₄)₂(H₂O)₂], (I), and dicaesium magnesium dioxalate tetrahydrate [tetra­aqua­bis(μ‐oxalato)­magnesium(II)­dicaesium(I)], [Cs₂Mg(C₂­O₄)₂(H₂O)₄], (II), have layered structures which are new among double‐metal oxalates. In (I), the Rb and Cr atoms lie on sites with imposed 2/m symmetry and the unique water molecule lies on a mirror plane; in (II), the Mg atom lies on a twofold axis. The two non‐equivalent Cr and Mg atoms both show octahedral coordination, with a mean Cr—O distance of 1.966 Å and a mean Mg—O distance of 2.066 Å. Dirubid­ium copper(II) dioxalate dihydrate [di­aqua­bis(μ‐oxalato)­copper(II)­dirubidium(I)], [Rb₂Cu(C₂O₄)₂(H₂O)₂], (III), is also layered and is isotypic with the previously described K₂‐ and (NH₄)₂Cu^II(C₂O₄)₂·2H₂O compounds. The two non‐equivalent Cu atoms lie on inversion centres and are both (4+2)‐coordinated. Hydro­gen bonds are medium‐strong to weak in the three compounds. The oxalate groups are slightly non‐planar only in the Cs–Mg compound, (II), and are more distinctly non‐planar in the K–Cu compound, (III).     

Linear chains in polymeric di­cyclo­hexyl­ammonium tri­butyl­(4‐oxo‐4H‐pyran‐2,6‐di­carboxyl­ato)­stannate and methyl­phenyl­ammonium tri­butyl(pyridine‐2,6‐di­carboxyl­ato)­stannate containing trigonal bipyramidal tin

catena‐Poly­[di­cyclo­hexyl­ammonium [tri­butyl­tin‐μ‐(4‐oxo‐4H‐pyran‐2,6‐di­carboxyl­ato‐O²:O⁶)]], (C₁₂­H₂₄N)­[Sn(C₇­H₂­O₆)(C₄H₉)₃], consists of 4‐oxo‐4H‐pyran‐2,6‐di­carboxyl­ato groups that axially link adjacent tri­butyl­tin units into a linear polyanionic chain. The ammonium counter‐ions surround the chain, and each cation forms a pair of hydrogen bonds to the double‐bond carbonyl O atoms of the same dianionic group. The chain propagates in a zigzag manner along the c axis of the monoclinic cell. In catena‐poly­[methyl­(phenyl)­ammonium [tri­butyl­tin‐μ‐(pyridine‐2,6‐di­carboxyl­ato‐O²:O⁶)]], (C₇H₁₀N)­[Sn(C₇H₃NO₄)­(C₄H₉)₃], the pyridine‐2,6‐di­carboxyl­ato groups also link the tri­butyl­tin groups into a chain, but the hydrogen‐bonded chain propagates linearly on the ac face of the monoclinic cell.     

Comparative X‐ray study of three nickel(II)–thio­cyanate compounds

Three cis nickel–di­thio­cyanate (SCN) complexes with different N,N′‐bidentate bases have been prepared and their crystal structures determined: bis(2,2′‐bi­pyridine‐N,N′)­bis­(thio­cyan‐­ato‐N)­nickel(II), [Ni(SCN)₂­(C₁₀H₈N₂)₂], bis(1,10‐phen­anthroline‐N,N′)­bis­(thio­cyanato‐N)­nickel(II), [Ni(SCN)₂­(C₁₂H₈N₂)₂], and bis(2,9‐di­methyl‐1,10‐phenanthroline‐N,N′)­bis­(thiocyanato‐N)nickel(II) mono­hydrate, [Ni(SCN)₂­(C₁₂H₈N₂)₂]·H₂O. Distortions due to ligand size are discussed.