The bis(acetonitrile‐κN)bis[N,N‐bis(diphenylphosphanyl)ethanamine‐κ2P,P′]iron(II) tetrabromidoferrate(II) and μ‐oxido‐bis[tribromidoferrate(III)] complex salts

Orange crystals of bis(acetonitrile‐κN)bis[N,N‐bis(diphenylphosphanyl)ethanamine‐κ²P,P′]iron(II) tetrabromidoferrate(II), [Fe(CH₃CN)₂(C₂₆H₂₅NP₂)₂][FeBr₄], (I), and red crystals of bis(acetonitrile‐κN)bis[N,N‐bis(diphenylphosphanyl)ethanamine‐κ²P,P′]iron(II) μ‐oxido‐bis[tribromidoferrate(III)], [Fe(CH₃CN)₂(C₂₆H₂₅NP₂)₂][Fe₂Br₆O], (II), were obtained from the same solution after prolonged exposure to atmospheric oxygen, resulting in partial oxidation of the [FeBr₄]²⁻ anion to the [Br₃FeOFeBr₃]²⁻ anion. The asymmetric unit of (I) consists of three independent cations, one on a general position and two on inversion centres, with two anions, required to balance the charge, located on general positions. The asymmetric unit of (II) consists of two independent cations and two anions, all on special positions. The geometric parameters within the coordination environments of the cations do not differ significantly, with the major differences being in the orientation of the phenyl rings on the bidentate phosphane ligand. The ethyl substituent in the cation of (II) and the Br atoms in the anions of (II) are disordered. The P—Fe—P bite angles represent the smallest angles reported to date for octahedral Fe^II complexes containing bidentate phosphine ligands with MeCN in the axial positions, ranging from 70.82 (3) to 70.98 (4)°. The average Fe—Br bond distances of 2.46 (2) and 2.36 (2) Å in the [FeBr₄]²⁻ and [Br₃FeOFeBr₃]²⁻ anions, respectively, illustrate the differences in the Fe oxidation states.     

Unusual O‐coordination of caffeine in tetra­kis(μ‐3,5‐dinitro­benzoato‐κ2O:O′)bis­[(caffeine‐κO)copper(II)]

The title compound {systematic name: tetra­kis(μ‐3,5‐dinitro­benzoato‐κ²O:O′)bis­[(3,7‐dihydro‐1,3,7‐trimethyl‐1H‐purine‐2,6‐dione‐κO²)copper(II)]}, [Cu₂(C₇H₃N₂O₆)₄(C₈H₁₀N₄O₂)₂], consists of paddle‐wheel dimeric tetra­kis(μ‐3,5‐dinitro­benzoato‐κ²O:O′)dicopper(II) units with O‐coordinated caffeine mol­ecules in both apical positions. The entire dimeric mol­ecule lies on a tetra­gonal inversion axis, and thus one nitro­benzoate anion with one Cu atom in a special position belong to the independent part of the mol­ecule. The caffeine ligand bonded to the Cu atom is disordered on a local twofold non‐crystallographic axis coincident with the axis. A π–π stacking inter­action is observed between the caffeine rings and adjacent symmetry‐related benzene rings of the 3,5‐dinitro­benzoate anions.     

Bis(2‐amino‐2‐thiazolinium) tetra‐μ‐formato‐κ8O:O′‐bis[(formato‐κO)copper(II)]

In the title dimeric compound, (C₃H₇N₂S)₂[Cu₂(CHO₂)₆], each Cu^II atom has a square‐pyramidal coordination, with the nonbridging formate ion at the apical position. The complex anion is located on a crystallographic inversion centre, with a Cu...Cu separation of 2.6566 (4) Å. 2‐Amino‐2‐thiazolinium cations connect complex anions via hydrogen bonds to form a ribbon running along the a axis.     

Two tetranuclear zinc clusters, [Zn4(μ3‐OEt)2(μ2‐MalO)4Et2] and [Zn4(μ3‐GueO)2(μ2‐GueO)2(μ2‐MalO)2(MalO)2]·2C7H8, containing defective dicubane core geometries (MalOH is maltol and GueOH is guethol)

The zinc alkoxide molecules in di‐μ₃‐ethanolato‐diethyltetrakis(μ₂‐2‐methyl‐4‐oxo‐4H‐pyran‐3‐olato‐κ³O³,O⁴:O³)tetrazinc(II), [Zn₄(C₂H₅)₂(C₂H₅O)₂(C₆H₅O₃)₄], (I), and bis(μ₃‐2‐ethoxyphenolato‐κ⁴O¹,O²:O¹:O¹)bis(μ₂‐2‐ethoxyphenolato‐κ³O¹,O²:O¹)bis(μ₂‐2‐methyl‐4‐oxo‐4H‐pyran‐3‐olato‐κ³O³,O⁴:O³)bis(2‐methyl‐4‐oxo‐4H‐pyran‐3‐olato‐κ²O³,O⁴)tetrazinc(II) toluene disolvate, [Zn₄(C₆H₅O₃)₄(C₈H₉O₂)₄]·2C₇H₈, (II), lie on crystallographic centres of inversion. The asymmetric units of (I) and (II) contain half of the tetrameric unit and additionally one molecule of toluene for (II). The Zn^II atoms are four‐ and six‐coordinated in distorted tetrahedral and octahedral geometries for (I), and six‐coordinated in a distorted octahedral environment for (II). The Zn^II atoms in both compounds are arranged in a defect dicubane Zn₄O₆ core structure composed of two EtZnO₃ tetrahedra and ZnO₆ octahedra for (I), and of four ZnO₆ octahedra for (II), sharing common corners. The maltolate ligands exist mostly in a μ₂‐bridging mode, while the guetholate ligands prefer a higher coordination mode and act as μ₃‐ and μ₂‐bridges.     

Bis(2,6‐diamino‐1H‐purin‐3‐ium) di‐μ‐croconato‐κ3O,O′:O′′;κ3O:O′,O′′‐bis[tetraaqua(croconato‐κ2O,O′)neodymium(III)]

The structure of the ionic title compound, (C₅H₇N₆)₂[Nd₂(C₅O₅)₄(H₂O)₈], consists of anionic dimers built around an inversion centre and is made up of an Nd^III cation, two croconate (croco) dianions and four water molecules (plus their inversion images), with two noncoordinated symmetry‐related 2,6‐diamino‐1H‐purin‐3‐ium (Hdap⁺) cations providing charge balance. Each Nd^III atom is bound to nine O atoms from four water and three croco units. The coordination polyhedron has the form of a rather regular monocapped square antiprism. The croconate anions are regular and the Hdap⁺ cation presents a unique, thus far unreported, protonation state. The abundance of hydrogen‐bonding donors and acceptors gives rise to a complex packing scheme consisting of dimers interlinked along the three crystallographic directions and defining anionic `cages' where the unbound Hdap⁺ cations lodge, linking to the mainframe via (N—H)_Hdap...O_water/croco and (O—H)_water...N_Hdap interactions.     

Bis­(acetato‐κ2O,O′)(2,9‐di­methyl‐1,10‐phenanthroline‐κ2N,N′)mercury(II) in two differently hydrated crystal forms

Two differently hydrated crystal forms of the title compound, viz. bis­(acetato‐κ²O,O′)(2,9‐di­methyl‐1,10‐phenanthroline‐κ²N,N′)­mercury(II), [Hg(C₂H₃O₂)₂(C₁₄H₁₂N₂)] or [HgAc₂(dmph)] [dmph is 2,3‐di­methyl‐1,10‐phenantroline (neocuproine) and Ac is acetate], (I), and tris­[bis­(acetato‐κ²O,O′)(2,9‐di­methyl‐1,10‐phenanthroline‐κ²N,N′)­mercury(II)] hexadecahydrate, [Hg(C₂H₃O₂)₂(C₁₄H₁₂N₂)]₃·16H₂O or [HgAc₂(dmph)]₃·16H₂O, (II), are presented. Both structures are composed of very simple monomeric units, which act as the building blocks of complex packing schemes stabilized by a diversity of π–π and hydrogen‐bonding interactions.     

A new hybrid organic–inorganic chain: [(phen)Cu–μ‐(κ2O:O′‐VP2O10H3)2–Cu(phen)]n

The structure of the title compound, poly[(dihydrogenphosphato‐κO)(μ₃‐hydrogenphosphato)di‐μ‐oxido‐(1,10‐phenanthroline)copper(II)vanadium(V)], [CuV(HPO₄)(H₂PO₄)O₂(C₁₂H₈N₂)]_n, is defined by [(phen)Cu–μ‐(κ²O:O′‐VP₂O₁₀H₃)₂–Cu(phen)] units (phen is 1,10‐phenanthroline), which are connected to neighbouring units through vanadyl bridges. Neighbouring chains have no covalent bonds between them, although they interdigitate through the phen groups viaπ–π interactions.     

Bis(2‐amino‐1H‐benzimidazol‐3‐ium) tetrakis(μ‐but‐2‐enoato)‐κ4O:O′;κ3O,O′:O;κ3O:O,O′‐bis[bis(but‐2‐enoato‐κ2O,O′)holmium(III)]

The title ionic compound, (C₇H₈N₃)₂[Ho₂(C₄H₅O₂)₈], is constructed from two almost identical independent centrosymmetric anionic dimers balanced by two independent 2‐amino‐1H‐benzimidazol‐3‐ium (Habim⁺) cations. The asymmetric part of each dimer is made up of one Ho^III cation and four crotonate (crot or but‐2‐enoate) anions, two of them acting in a simple η²‐chelating mode and the remaining two acting in two different μ₂:η² fashions, viz. purely bridging and bridging–chelating. Symmetry‐related Ho^III cations are linked by two Ho—O—Ho and two Ho—O—C—O—Ho bridges which lead to rather short intracationic Ho...Ho distances [3.8418 (3) and 3.8246 (3) Å]. In addition to the obvious Coulombic interactions linking the cations and anions, the isolated [Ho₂(crot)₈]²⁻ and Habim⁺ ions are linked by a number of N—H...O hydrogen bonds, in which all N—H groups of the cation are involved as donors and all (simple chelating) crot O atoms are involved as acceptors. These interactions result in compact two‐dimensional structures parallel to (110), which are linked to each other by weaker π–π contacts between Habim⁺ benzene groups.     

Poly[di‐μ‐aqua‐μ‐1,2‐bis(pyridin‐4‐yl)ethene‐κ2N:N′‐tetrakis(4‐iodobenzoato‐κ2O,O′)dicadmium]

Colourless crystals of the title compound, [Cd₂(C₇H₄IO₂)₄(C₁₂H₁₀N₂)(H₂O)₂]_n, were obtained by the self‐assembly of Cd(NO₃)₂·4H₂O, 1,2‐bis(pyridin‐4‐yl)ethene (bpe) and 4‐iodobenzoic acid (4‐IBA). Each Cd^II atom is seven‐coordinated in a pentagonal–bipyramidal coordination environment by four carboxylate O atoms from two different 4‐IBA ligands, two O atoms from two water molecules and one N atom from a bpe ligand. The Cd^II centres are bridged by the aqua molecules and bpe ligands, which lie across centres of inversion, to give a two‐dimensional net. Topologically, taking the Cd^II atoms as nodes and the μ‐aqua and μ‐bpe ligands as linkers, the two‐dimensional structure can be simplified as a (6,3) network.     

Di‐μ2‐sulfito‐κ8O,O′:O′,O′′‐bis[(2,4,6‐tri‐2‐pyrid­yl‐1,3,5‐triazine‐κ3N2,N1,N6)cadmium(II)] octa­hydrate

The title compound, [Cd₂(SO₃)₂(C₁₈H₁₂N₆)₂]·8H₂O, is a dimer built up around a symmetry center, where the sulfite anion displays a so far unreported coordination mode in metal‐organic complexes; the anion binds as a μ₂‐sulfite‐κ⁴O,O′:O′,O′′ ligand to two symmetry‐related seven‐coordinate Cd^II cations, binding through its three O atoms by way of two chelate bites with an O atom in common, which acts as a bridge. The cation coordination is completed by a 2,4,6‐tri‐2‐pyridyl‐1,3,5‐triazine ligand acting in its usual tridentate mode.     

catena‐Poly­[[bis­(hexa­fluoro­acetyl­acetonato‐κ2O,O′)­zinc(II)]‐μ‐4,4′‐bi­pyridine‐κ2N:N′]

The structure of the title compound, catena‐poly[[bis(1,1,1,5,5,5‐hexafluoropentane‐2,4‐dionato‐κ²O,O′)zinc(III)]‐μ‐4,4′‐bipyridine‐κ²N:N′], [Zn(C₅HF₆O₂)₂(C₁₀H₈N₂)]_n, con­sists of polymeric chains, running in two perpendicular directions, organized as planes normal to the tetragonal axis. The elemental unit of the chains is the zinc(II) coordination polyhedron bisected by a twofold symmetry axis, and thus only half of the unit is independent. The octahedral coordination geometry of the metal centre is composed of two oxy­gen‐chelating (symmetry‐related) hexa­fluoro­acetyl­acetonate groups and two translationally related 4,4′‐bi­pyridine groups, which act as connecting agents in the polymer structure. The stabilization of this architecture of chains and planes is associated with a number of weak C—H⋯O and C—H⋯F hydrogen bonds.     

Tetra‐μ‐2‐fluoro­benzoato‐bis[aqua(4,4′‐bi­pyridine)(2‐fluorobenzoato)lanthanum(III)]

Each La³⁺ ion in the title complex, tetra‐μ‐2‐fluorobenzoato‐κ¹⁰O:O′;O:O,O′;O:O′;O,O′:O′‐bis[aqua(4,4′‐bipy­ridine‐κN)(2‐fluorobenzoato‐κO)lanthanum(II)], [La(C₇H₄FO₂)₆(C₁₀H₈N₂)₂(H₂O)₂], is coordinated by six O atoms from the carboxyl­ate groups of five 2‐fluoro­benzoate ligands, one O atom from a water mol­ecule and one N atom from a 4,4′‐bi­pyridine mol­ecule, thus forming a dimeric mol­ecule. An infinite one‐dimensional dimeric supramolecular chain is formed via intermolecular hydrogen bonds.     

catena‐Poly[potassium [copper(II)‐μ‐isothiocyanato‐μ‐N‐salicylidene‐β‐alaninato(2–)]]

The title polymeric compound, catena‐poly­[dipotassium [bis­[μ‐N‐salicyl­idene‐β‐alaninato(2−)]‐κ⁴O,N,O′:O′′;κ⁴O′′:O,N,O′‐dicopper(II)]‐di‐μ‐iso­thio­cyanato‐κ²N:S;κ²S:N], {K[Cu(NCS)(C₁₀H₉NO₃)]}_n, consists of [iso­thio­cyanato(N‐salicyl­idene‐β‐alaninato)copper(II)]⁻ anions connected through the two three‐atom thio­cyanate (μ‐NCS) and the two anti,anti‐μ‐­carboxyl­ate bridges into infinite one‐dimensional polymeric anions, with coulombically interacting K⁺ counter‐ions with coordination number 7 constrained between the chains. The Cu^II atoms adopt a distorted tetragonal–bipyramidal coordination, with three donor atoms of the tridentate Schiff base and one N atom of the bridging μ‐NCS ligand in the basal plane. The first axial position is occupied by a thio­cyanate S atom of a symmetry‐related μ‐NCS ligand at an apical distance of 2.9770 (8) Å, and the second position is occupied by an O atom of a bridging carboxyl­ate group from an adjacent coordination unit at a distance of 2.639 (2) Å.     

catena‐Poly[[(acetato‐κ2O,O′)triaquabarium(II)]‐μ3‐acetato‐κ4O:O,O′:O′]

The present form of barium acetate, formulated as [Ba(C₂H₃O₂)₂(H₂O)₃]_n, is the largest reported hydrate of the salt and this leads to a distinct structural behaviour setting it apart from the rest of the family. The compound is a linear polymer with a nine‐coordinate Ba(O_aqua)₃(O_acetate)₆ monomer unit. The non‐H part of the structure is ordered according to C2/m symmetry, while the disordered water H atoms only abide by this symmetry in a statistical sense. Each molecule is halved by a mirror plane bisecting the Ba centre, one water molecule and one acetate ligand, while containing the other acetate ligand. The chains are interconnected by a disordered water–water/acetate O—H...O hydrogen‐bonding network involving all water H atoms. The structure and stability of this phase are compared with the other known acetates of barium which differ in the degree of hydration.     

Tetra­kis(μ2‐1,8‐naphthyridine)‐1:2κ4N:N′;3:4κ4N:N′‐bis­(μ2‐salicylato)‐1:4κ2O:O′;2:3κ2O:O′‐tetrakis­(salicylic acid)‐1κO,2κO,3κO,4κO‐tetra­silver(I)(4 Ag—Ag)

The title complex, [Ag₄(C₇H₅O₃)₂(C₈H₆N₂)₄(C₇H₆O₃)₄], lies about an inversion centre and has a unique tetra­nuclear structure consisting of four Ag^I atoms bridged by four N atoms from two 1,8‐naphthyridine (napy) ligands to form an N:N′‐bridge and four O atoms from two salicylate (SA) ligands to form an O:O′‐bridge. The Ag atoms have distorted octa­hedral coordination geometry. The centrosymmetric Ag₄ ring has Ag—Ag separations of 2.772 (2) and 3.127 (2) Å, and Ag—Ag—Ag angles of 107.70 (4) and 72.30 (4)°. All SA hydroxy groups take part in intra­molecular O—H⋯O hydrogen bonding. In the crystal packing, the napy rings are oriented parallel and overlap one another. These π–π inter­actions, together with weak inter­molecular C—H⋯O contacts, stabilize the crystal structure.     

(μ‐1,2‐Dimethoxyethane‐κ2O:O′)bis[(1,2‐dimethoxyethane‐κ2O,O′)tris(1,1,1,5,5,5‐hexafluoro‐4‐oxopent‐2‐en‐2‐olato‐κ2O,O′)cerium(III)]

A previous analysis [Fatila et al. (2012). Dalton Trans. 41 , 1352–1362] of the title complex, [Ce₂(C₅HF₆O₂)₆(C₄H₁₀O₂)₃], had identified it as Ce(hfac)₃(dme)_1.5 according to the ¹H NMR integration [hfac = 1,1,1,5,5,5‐hexafluoroacetylacetonate (1,1,1,5,5,5‐hexafluoro‐4‐oxopent‐2‐en‐2‐olate) and dme = 1,2‐dimethoxyethane]; however, it was not possible to determine the coordination environment unambiguously. The structural data presented here reveal that the complex is a binuclear species located on a crystallographic inversion center. Each Ce^III ion is coordinated to three hfac ligands, one bidentate dme ligand and one monodentate (bridging) dme ligand, thus giving a coordination number of nine (CN = 9) to each Ce^III ion. The atoms of the bridging dme ligand are unequally disordered over two sets of sites. In addition, in two of the –CF₃ groups, the F atoms are rotationally disordered over two sets of sites. This is the first crystal structure of a binuclear lanthanide β‐diketonate with a bridging dme ligand.     

Bis(acesulfamato‐κ2N3,O4)bis­(2‐amino­pyrimidine‐κN1)copper(II)

In the crystal structure of the title compound, bis­(2‐amino­pyrimidine‐κN¹)bis­[6‐meth­yl‐1,2,3‐oxathia­zin‐4(3H)‐one 2,2‐dioxide(1−)‐κ²N³,O⁴]copper(II), [Cu(C₄H₄NO₄S)₂(C₄H₅N₃)₂], the first mixed‐ligand complex of acesulfame, 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 by the Jahn–Teller effect. The equatorial plane is formed by the N atoms of two amino­pyrimidine (ampym) ligands and by the weakly basic carbonyl O atoms of the acesulfamate ligands, while the more basic deprotonated N atoms of these ligands are in the elongated axial positions with a strong misdirected valence. The crystal is stabilized by pyrimidine ring stacking and by inter­molecular hydrogen bonding involving the NH₂ moiety of the ampym ligand and the carbon­yl O atom of the acesulfamate moiety.     

A novel titanium–μ‐O–zirconium complex: bis(μ‐methyliminodiethanolato‐1κ3O,N,O′;1:2κ2O)(methyliminodiethanolato‐2κ3O,N,O′)dipropanolato‐1κO,2κO‐titanium(IV)zirconium(IV)

The title compound, [TiZr(C₅H₁₁NO₂)₃(C₃H₇O)₂], contains three methyl­imino­diethano­late ligands, two in different μ‐oxo bridging coordination modes and one bound only to the Ti atom. The Ti and Zr atoms have distorted octahedral and pentagonal–bipyramidal coordinations, respectively, which share edges. As well as some conformational disorder in the carbon chains, there is chemical disorder at one Ti site, with a mix of n‐ and isopropanolate ligands.     

Di‐μ‐acetato‐O:O′‐di‐μ‐acetato‐O,O′:O′‐bis­{[(cyclo­penta­dienyl)tris­(di­methyl­phosphito‐P)­cobalt‐O,O′,O′′]neodymium(III)}

In the title compound, [{η⁵‐CpCo[P(O)(OMe)₂]₃}Nd(O₂CCH₃)₂]₂, with a centrosymmetric mol­ecule, each Nd atom has an eight‐coordination environment, surrounded by a tripodal {L_OMe = CpCo[P(O)(OMe)₂]₃} and four bridging acetato ligands. The coordination geometry around each Nd centre is described as a distorted square‐antiprism and the two different types of acetato ligands have μ‐O:O′‐ and μ‐O,O′:O′‐acetato coordination modes. The Nd—O distances are in the range 2.378 (4)–2.594 (5) Å and the Nd?Nd distance is 3.9913 (6) Å.     

First heterobimetallic AgI–CoIII coordination compound with both bridging and terminal –NO2 coordination modes: synthesis,characterization, structural and computational studies of (PPh3)2AgI–(μ‐κ2O,O′:κN‐NO2)–CoIII(DMGH)2(κN‐NO2)

An unusual heterobimetallic bis(triphenylphosphane)(NO₂)Ag^I–Co^III(dimethylglyoximate)(NO₂) coordination compound with both bridging and terminal –NO₂ (nitro) coordination modes has been isolated and characterized from the reaction of [CoCl(DMGH)₂(PPh₃)] (DMGH₂ is dimethylglyoxime or N,N′‐dihydroxybutane‐2,3‐diimine) with excess AgNO₂. In the title compound, namely bis(dimethylglyoximato‐1κ²O,O′)(μ‐nitro‐1κN:2κ²O,O′)(nitro‐1κN)bis(triphenylphosphane‐2κP)cobalt(III)silver(I), [AgCo(C₄H₇N₂O₂)₂(NO₂)₂(C₁₈H₁₅P)₂], one of the ambidentate –NO₂ ligands, in a bridging mode, chelates the Ag^I atom in an isobidentate κ²O,O′‐manner and its N atom is coordinated to the Co^III atom. The other –NO₂ ligand is terminally κN‐coordinated to the Co^III atom. The structure has been fully characterized by X‐ray crystallography and spectroscopic methods. Density functional theory (DFT) and time‐dependent density functional theory (TD‐DFT) have been used to study the ground‐state electronic structure and elucidate the origin of the electronic transitions, respectively.