Crystal structures and spectroscopic characterization of MBr2(CNXyl)n (M = Fe and Co,n = 4; M = Ni,n = 2; Xyl = 2,6‐dimethylphenyl), and of formally zero‐valent iron as a cocrystal of Fe(CNXyl)5 and Fe2(CNXyl)9

Structures and spectroscopic characterization of the divalent complexes cis‐dibromidotetrakis(2,6‐dimethylphenyl isocyanide)iron(II) dichloromethane 0.771‐solvate, [FeBr₂(C₉H₉N)₄]·0.771CH₂Cl₂ or cis‐FeBr₂(CNXyl)₄·0.771CH₂Cl₂ (Xyl = 2,6‐dimethylphenyl), trans‐dibromidotetrakis(2,6‐dimethylphenyl isocyanide)iron(II), [FeBr₂(C₉H₉N)₄] or trans‐FeBr₂(CNXyl)₄, trans‐dibromidotetrakis(2,6‐dimethylphenyl isocyanide)cobalt(II), [CoBr₂(C₉H₉N)₄] or trans‐CoBr₂(CNXyl)₄, and trans‐dibromidobis(2,6‐dimethylphenyl isocyanide)nickel(II), [NiBr₂(C₉H₉N)₂] or trans‐NiBr₂(CNXyl)₂, are presented. Additionally, crystals grown from a cold diethyl ether solution of zero‐valent Fe(CNXyl)₅ produced a structure containing a cocrystallization of mononuclear Fe(CNXyl)₅ and the previously unknown dinuclear [Fe(CNXyl)₃]₂(μ₂‐CNXyl)₃, namely pentakis(2,6‐dimethylphenyl isocyanide)iron(0) tris(μ₂‐2,6‐dimethylphenyl isocyanide)bis[tris(2,6‐dimethylphenyl isocyanide)iron(0)], [Fe(C₉H₉N)₅][Fe₂(C₉H₉N)₉]. The (M)C—N—C(Xyl) angles of the isocyanide ligand are nearly linear for the metals in the +2 oxidation state, for which the ligands function essentially as pure donors. The νCN stretching frequencies for these divalent metal isocyanides are at or above that of the free ligand. Relative to Fe^II, in the structure containing iron in the formally zero‐valent oxidation state, the Fe—C bond lengths have shortened, the C[triple‐bond]N bond lengths have elongated, the (M)C—N—C(Xyl) angles of the terminal CNXyl ligands are more bent, and the νCN stretching frequencies have shifted to lower energies, all indicative of substantial M(dπ)→π* backbonding.     

Platinum complexes of oxopurines: cis‐bis(theophyllinato‐N7)bis(triphenylphosphine)platinum(II) and cis‐chloro(theobrominato‐N1)bis(triphenylphosphine)platinum(II) ethanol hemisolvate

The syntheses and structures of two mixed‐ligand complexes of platinum(II) with deprotonated oxopurine bases and tri­phenyl­phosphine are reported, namely the theophyllinate complex cis‐bis(1,2,3,6‐tetra­hydro‐1,3‐di­methyl­purine‐2,6‐dionato‐κN⁷)­bis(tri­phenyl­phosphine‐κP)­platinum(II), [Pt(C₇H₇N₄O₂)₂(C₁₈H₁₅P)₂], (I), and the theobrominate complex cis‐chloro(1,2,3,6‐tetrahydro‐3,7‐dimethylpurine‐2,6‐dionato‐κN¹)­bis(tri­phenyl­phosphine‐κP)­platinum(II) ethanol hemisolvate, [PtCl(C₇H₇N₄O₂)(C₁₈H₁₅P)₂]·0.5C₂H₅OH, (II). In (I), the coordination geometry of Pt is square planar, formed by the two coordinating N atoms of the theophyl­linate anions in a cis arrangement and two P atoms from the tri­phenyl­phosphine groups. In (II), there are two crystallographically independent mol­ecules. They both exhibit a square‐planar coordination geometry around Pt involving one Cl atom, the coordinating N atom of the theobrominate anion and two P atoms from the tri­phenyl­phosphine groups. The two tri­phenyl­phosphine groups are arranged in a cis configuration in both structures. The heterocyclic rings are rotated with respect to the coordination plane of the metal by 82.99 (8) and 88.09 (8)° in complex (I), and by 85.91 (16) and 88.14 (18)° in complex (II). Both structures are stabilized by intramolecular stacking interactions involving the purine rings and the phenyl rings of adjacent tri­phenyl­phosphine moieties.     

Synthesis and Structure of the Tetrameric [Cp*V(μ‐F)2]4 (Cp* = C5Me5); Preparation of the Imido Molybdenum Fluoride [(2,6‐i‐Pr2C6H3N)2MoF2] · THF and the Structural Investigation of [(2,6‐i‐Pr2C6H3N)6Mo4(μ3‐F)2Me2(μ‐O)4]

Treating [Cp*V(μ‐Cl)₂]₃ (Cp* = C₅Me₅) and [(2,6‐i‐Pr₂C₆H₃N)₂MoMe₂], respectively, with Me₃SnF afforded the title compounds [Cp*V(μ‐F)₂]₄ ( 1 ) and [(2,6‐i‐Pr₂C₆H₃N)₂MoF₂] · THF ( 2 ). 1 has a tetrameric structure, in which four V atoms can be regarded as being arranged at the vertices of a distorted tetrahedron, with four long edges bridged by one F atom and each of the other two short edges bridged by two F atoms with a mean V–F bond length of 2.00 Å. A hydrolyzed product of 2 , [(2,6‐i‐Pr₂C₆H₃N)₆Mo₄(μ₃‐F)₂Me₂(μ‐O)₄] ( 3 ) was characterized by elemental analyses and X‐ray single crystal study. The X‐ray diffraction analysis reveals that 3 has a unique tetranuclear structure, containing two five and two six coordinated Mo atoms connecting each other by four μ‐O and two μ₃‐F atoms. The geometries around the two Mo atoms can be described having distorted trigonal bipyramidal and distorted octahedral coordination spheres, respectively. The Mo–(μ‐O) bond lengths are 1.813 Å (average) for five coordinated Mo atoms and 2.030 Å (average) for those of six coordinated, respectively, indicating an additional π bonding between five coordinated Mo atoms and the μ‐O atoms. The Mo–(μ₃‐F) distances range from 2.291 to 2.352 Å.     

Destruktive Komplexierung des dimeren Diorganylzinn(IV)‐hydroxids [Me2Sn(A)(μ‐OH)]2 (HA = Benzol‐1,2‐disulfonsäureimid): Bildung und Strukturen der Einkernkomplexe [Me2Sn(A)2(OPPh3)2] und [Me2Sn(phen)2]2⊕ · 2 A⊖ · MeCN

Polysulfonylamines. CXVI. Destructive Complexation of the Dimeric Diorganyltin(IV) Hydroxide [Me₂Sn(A)(μ‐OH)]₂ (HA = Benzene‐1,2‐disulfonimide): Formation and Structures of the Mononuclear Complexes [Me₂Sn(A)₂(OPPh₃)₂] and [Me₂Sn(phen)₂]^2⊕ · 2 A^⊖ · MeCN Destructive complexation of the dimeric hydroxide [Me₂Sn(A)(μ‐OH)]₂, where A^⊖ is deprotonated benzene‐1,2‐disulfonimide, with two equivalents of triphenylphosphine oxide or 1,10‐phenanthroline in hot MeCN produced, along with Me₂SnO and water, the novel coordination compounds [Me₂Sn(A)₂(OPPh₃)₂] ( 3 , triclinic, space group P 1) and [Me₂Sn(phen)₂]^2⊕ · 2 A^⊖ · MeCN ( 4 , monoclinic, P2₁/c). In the uncharged all‐trans octahedral complex 3 , the heteroligands are unidentally O‐bonded to the tin atom, which resides on a crystallographic centre of inversion [Sn–O(S) 227.4(2), Sn–O(P) 219.6(2) pm, cis‐angles in the range 87–93°; anionic ligand partially disordered over two equally populated sites for N, two S and non‐coordinating O atoms]. The cation occurring in the crystal of 4 has a severely distorted cis‐octahedral C₂N₄ coordination geometry around tin and represents the first authenticated example of a dicationic tin(IV) dichelate [R₂Sn(L–L′)₂]^2⊕ to adopt a cis‐structure [C–Sn–C 108.44(11)°]. The five‐membered chelate rings are nearly planar, with similar bite angles of the bidentate ligands, but unsymmetric Sn–N bond lengths, each of the longer bonds being trans to a methyl group [ring 1: N–Sn–N 71.24(7)°, Sn–N 226.81(19) and 237.5(2) pm; ring 2: 71.63(7)°, 228.0(2) and 232.20(19) pm]. In both structures, the bicyclic and effectively C_S symmetric A^⊖ ions have their five‐membered rings distorted into an envelope conformation, with N atoms displaced by 28–43 pm from the corresponding C₆S₂ mean plane.     

Synthesis,structure and cytotoxic activity of binuclear phenyltin(IV) complexes with N,N′‐bis(2‐hydroxybenzyl)‐1,2‐ethanebis(dithiocarbamate) ligand

Two new dinuclear phenyltin(IV) complexes derived from N,N′‐bis(2‐hydroxybenzyl)‐1,2‐ethanebis(dithiocarbamate) ligand, [2‐HOC₆H₄CH₂N(CS₂SnPh₃)CH₂]₂ ( 1 ) and [2‐HOC₆H₄CH₂N(CS₂SnClPh₂)CH₂]₂ ( 2 ) have been synthesized and characterized by elemental analysis, IR and NMR (¹H, ¹³C and ¹¹⁹Sn) spectra. The crystal structures of complexes 1 and 2 were determined by X‐ray single crystal diffraction and show that the dithiocarbamate ligand is coordinated to the tin atom in the anisobidentate manner and the tin atom is five‐coordinated. The coordination geometry of tin atom is best described as an intermediate between trigonal bipyramidal and square pyramidal with τ‐values of 0.63 and 0.53, respectively. Intermolecular hydrogen bonds (O H···S and O H···Cl) in 1 and 2 connect neighboring molecules into a one‐dimensional supramolecular chain with the centrosymmetric cyclic motifs. Complex 1 has potent in vitro cytotoxic activity against two human tumor cell lines, CoLo205 and Bcap37, while complex 2 displays weak cytotoxic activity. Copyright © 2011 John Wiley & Sons, Ltd.     

Transformations of the chameleon ligand 1,10‐phenanthroline‐5,6‐dione/diol: cis‐dichlorido(1,10‐phenanthroline‐5,6‐dione‐κ2N,N′)‐trans‐dipyridinecobalt(II) pyridine disolvate prepared from the diol

The title compound, [CoCl₂(C₅H₅N)₂(C₁₂H₆N₂O₂)]·2C₅H₅N, is a neutral Co^II complex with two chloride anions coordinated in a cis fashion, two pyridine ligands in trans positions and a chelating 1,10‐phenanthroline‐5,6‐dione ligand that completes the octahedral coordination geometry. Two pyridine solvent molecules reside in channels (about 7 × 4 Å wide; the closest atom–atom distance within the channel is 10 Å). The three‐dimensional structure supporting these channels is held together by C—H...Cl [3.466 (8)–3.670 (9) Å] and C—H...O [3.014 (9)–3.285 (8) Å] hydrogen bonds, and can be viewed as a CsCl or bcu (body‐centred cubic) net.     

(Aceto­nitrile)­[2,6‐bis­(pyrazol‐1‐yl)­pyridine](isonicotin­amide)copper(II)–tetra­fluoro­borate–aceto­nitrile (1/2/2)

Molecules of the title compound, [Cu(C₂H₃N)(C₁₁H₉N₅)(C₆H₆N₂O)](BF₄)₂·2C₂H₃N, comprise (aceto­nitrile)[2,6‐bis(pyrazol‐1‐yl)­pyridine](isonicotin­amide)copper(II) cations, tetra­fluoro­borate anions and lattice aceto­nitrile mol­ecules. The cations have distorted square‐pyramidal geometries in which the N₃‐donor, viz. 2,6‐bis­(pyrazol‐1‐yl)­pyridine, and the N‐donor, viz. the isonicotin­amide ligand, occupy the four basal positions, with the coordinated aceto­nitrile N‐donor atom occupying the apical position. Pairs of cations are linked by N—H?F hydrogen bonds through tetra­fluoro­borate anions, forming centrosymmetric dimers, which are further linked by C—H?O hydrogen bonds into two‐dimensional undulating sheets, three of which interpenetrate to generate a two‐dimensional network.     

Two isomorphous crotonatolanthanide complexes: tetra‐μ‐but‐2‐enoato‐bis[diaqua(but‐2‐enoato)Ln]–2,6‐diaminopurine (1/2) (Ln = Dy and Ho)

The title isomorphous compounds, tetra‐μ‐but‐2‐enoato‐bis[diaqua(but‐2‐enoato)dysprosium(III)]–2,6‐diaminopurine (1/2), [Dy₂(C₄H₅O₂)₆(H₂O)₄]·2C₅H₆N₆, and tetra‐μ‐but‐2‐enoato‐bis[diaqua(but‐2‐enoato)holmium(III)]–2,6‐diaminopurine (1/2), [Ho₂(C₄H₅O₂)₆(H₂O)₄]·2C₅H₆N₆, consist of [Ln(crot)₃(H₂O)₂]₂ dimers (crot is crotonate or but‐2‐enoate; Ln is the lanthanide cation), built up around inversion centres and completed by 2,6‐diaminopurine molecules. The lanthanide cation is coordinated by three chelating crotonate units and two water molecules. One of the chelating carboxylate groups acts also in a bridging mode sharing one O atom with both cations and the final result is a pair of DyO₉ tricapped prismatic polyhedra linked to each other through a central (Dy—O)₂ loop. A feature of the structures is the existence of a complex intermolecular interaction scheme involving two sets of tightly interlinked non‐intersecting one‐dimensional structures, one of them formed by the [Dy(crot)₃(H₂O)₂]₂ dimers (running along [100] and linked by O—H...O hydrogen bonds) and the second formed by 2,6‐diaminopurine molecules (evolving along [010] linked by N—H...N hydrogen bonds).     

First Characterization of an Extended Ammonium‐Ammonia Complex [{NH4(NH3)4}+(μ‐NH3)2] in the Crystal Structure of [NH4(NH3)4][Co(C2B9H11)2] · 2 NH3

The compound [NH₄(NH₃)₄][Co(C₂B₉H₁₁)₂] · 2 NH₃ ( 1 ) was prepared by the reaction of Na[Co(C₂B₉H₁₁)₂] with a proton‐charged ion‐exchange resin in liquid ammonia. The ammoniate 1 was characterized by low temperature single‐crystal X‐ray structure analysis. The anionic part of the structure consists of [Co(C₂B₉H₁₁)₂]^‐ complexes, which are connected via C‐H···H‐B dihydrogen bonds. Furthermore, 1 contains an infinite equation/tex2gif-stack-2.gif[{NH₄(NH₃)₄}⁺(μ‐NH₃)₂] cationic chain, which is formed by [NH₄(NH₃)₄]⁺ ions linked by two ammonia molecules. The N‐H···N hydrogen bonds range from 1.92 to 2.71Å (DHA = Donor···Acceptor angles: 136‐176°). Additional N‐H···H‐B dihydrogen bonds are observed (H···H: 2.3‐2.4Å).     

Two dimeric CuII benzoate derivatives solvated with aceto­nitrile

The title compounds, tetrakis(μ‐benzoato‐O:O′)­bis(2,6‐di­amino­pyridine)‐1κN,2κN‐dicopper(II)–aceto­nitrile (1/2), [Cu₂(C₇H₅O₂)₄(C₅H₇N₃)₂]·2C₂H₃N, (I), and bis­(aceto­nitrile)‐1κN,2κN‐tetrakis(μ‐benzoato‐O:O′)­dicopper(II)–aceto­nitrile (1/1.5), [Cu₂(C₇H₅O₂)₄(C₂H₃N)₂]·1.5C₂H₃N, (II), crystallize as aceto­nitrile solvates exhibiting different stability. They have similar molecular structures with discrete dimeric units located at crystallographic inversion centres. The copper ions are bridged by four benzoate groups and neutral N‐donor ligands, viz. 2,6‐di­amino­pyridine in (I) and aceto­nitrile in (II), are coordinated at apical positions. The diverse stability is probably due to hydrogen‐bond interactions of the solvated aceto­nitrile mol­ecules with neighbouring dimers in compound (I).     

Di‐μ‐chloro‐bis­{bis­[2,5‐bis­(4‐methoxy­phenyl)‐1,3,4‐oxadiazole‐κ2C2′,N]iridium(III)] dichloro­methane disolvate

In the title compound, [Ir₂(C₁₆H₁₃N₂O₃)₄Cl₂]·2CH₂Cl₂, the two Ir atoms, 3.7075 (6) Å apart, are bridged by two Cl atoms which straddle a twofold axis of rotation through the two Ir atoms. Each Ir centre resides in a distorted octa­hedral environment completed by two chelating 2,5‐bis­(4‐methoxy­phenyl)‐1,3,4‐oxadiazole ligands, with trans‐N—N and cis‐C—C dispositions. In the stacking structure, there are two types of hydrogen bonds, involving the meth­oxy substitutent, an N atom of the oxadiazole ring and the dichloro­methane solvent mol­ecules.     

Coordination behaviour of the 2‐(N,N‐dimethylaminomethyl)phenyl ligand towards the di‐t‐butylchlorotin(IV) moiety

{2‐(N,N‐Dimethylaminomethyl)phenyl}(di‐t‐butyl)tin(IV)chloride, {2‐[(CH₃)₂NCH₂]C₆H₄}Sn(t‐Bu)₂ Cl, has been prepared and characterized using NMR and crystallography. This is the first example of a triorganotin(IV) halide containing the 2‐[(CH₃)₂NCH₂]C₆H₄—group as a C,N‐chelating ligand with a weak intramolecular Sn—N interaction because of the steric hindrance of t‐butyl groups. The interatomic Sn—N distance is elongated to 2.904(14) Å and the central tin atom is distorted trigonal bipyramidal. Copyright © 2004 John Wiley & Sons, Ltd.     

[N,N′‐Bis(3‐aminopropyl)ethylenediamine‐κ4N,N′,N′′,N′′′](trithiocyanurato‐κ2N,S)zinc(II) ethanol solvate

In the crystal structure of the title compound, [N,N′‐bis(3‐­amino­propyl)­ethyl­enedi­amine‐κ⁴N,N′,N′′,N′′′][1,3,5‐triazine‐2,4,6(1H,3H,5H)‐tri­thionato(2−)‐κ²N,S]­zinc(II) ethanol sol­vate, [Zn(C₈H₂₂N₄)₂(C₃HN₃S₃)]·C₂H₆O, the Zn^II atom is octa­hedrally coordinated by four N atoms [Zn—N = 2.104 (2)–2.203 (2) Å] of a tetradentate N‐donor N,N′‐bis(3‐­amino­propyl)­ethyl­enedi­amine (bapen) ligand and by two S and N atoms [Zn—S = 2.5700 (7) Å and Zn—N = 2.313 (2) Å] of a tri­thio­cyanurate(2−) (ttcH²⁻) dianion bonded as a bidentate ligand in a cis configuration. The crystal structure of the compound is stabilized by a network of hydrogen bonds.     

Two novel bis­(2,9‐dimeth­yl‐1,10‐phenanthroline)copper(I) complexes: [Cu(dmp)2]2(PF6)2·0.5(bpmh)·CH3CN and [Cu(dmp)2][N(CN)2]

Two new salts of the cation [Cu^I(dmp)₂]⁺ (dmp is 2,9‐dimeth­yl‐1,10‐phenanthroline, C₁₄H₁₂N₂), namely bis­[bis­(2,9‐dimeth­yl‐1,10‐phenanthroline‐κ²N,N′)copper(I)] bis­(hexa­fluorophos­phate) hemi[bis­(4‐pyridylmethyl­idene)hydrazine] acetonitrile solvate, [Cu(C₁₄H₁₂N₂)₂]₂(PF₆)₂·0.5C₁₂H₁₀N₄·C₂H₃N or [Cu(dmp)₂]₂(PF₆)₂·0.5(bpmh)·CH₃CN [bpmh is bis­(4‐pyridylmethyl­idene)hydrazine, C₁₂H₁₀N₄], (I), and bis­(2,9‐dimeth­yl‐1,10‐phenanthroline‐κ²N,N′)copper(I) dicyanamide, [Cu(C₁₄H₁₂N₂)₂](C₂N₃) or [Cu(dmp)₂][N(CN)₂], (II), are reported. The Cu—N bond lengths and the distortion from idealized tetra­hedral geometry of the dmp ligands are discussed and compared with related compounds. The bpmh molecule in (I) is π–π stacked with a dmp ligand at a distance of 3.4 Å, rather than coordinated to the metal atom. The molecule lies across an inversion center in the crystal. In (II), the normally coordinated dicyanamide mol­ecule is present as an uncoordinated counter‐ion.     

trans‐Di­chloro‐cis‐bis(3,6‐di­methyl­carbazolyl)‐cis‐bis­(tetra­hydro­furan)­zirconium(IV) benzene sesquisolvate

In the title compound, [ZrCl₂(C₁₄H₁₂N)₂(C₄H₈O)₂]·1.5C₆H₆, the Zr atom is pseudo‐octahedral, with two Cl atoms in trans positions and two tetra­hydro­furan mol­ecules in cis positions. The two 3,6‐di­methyl­carbazolyl ligands are in cis positions and are canted with respect to one another. The two Zr—N distances are 2.1148 (18) and 2.1236 (18) Å, and the N—Zr—N angle is 95.08 (7)°. The title compound crystallizes as the benzene solvate, with one of the benzene mol­ecules positioned on an inversion center.     

Bis(dimethyl sulfoxide‐S)tetrakis(μ‐p‐hydroxybenzoato‐O:O′)dirhodium(II)–tetrakis(μ‐butyrato‐O:O′)bis(dimethyl sulfoxide‐S)dirhodium(II) cocrystal ethanol disolvate

The title structure, [Rh₂(C₇H₅O₃)₄(C₂H₆OS)₂]·[Rh₂(C₄H₇­O₂)₄(C₂H₆OS)₂]·2C₂H₆O, contains two discrete neutral Rh–Rh dimers cocrystallized as the ethanol disolvate. Each dimer is situated on an inversion center. The butyrate chain displays disorder in one C‐atom position. In each dimer, the di­methyl sulfoxide ligand (dmso) is bound via S, as expected. The ethanol is a hydrogen‐bond acceptor for one p‐hydroxy­benzoate hydroxyl group and acts as a hydrogen‐bond donor to the dmso O atom of a neighboring p‐hydroxy­benzoate dirhodium complex. A third hydrogen bond is formed from the other p‐hydroxy­benzoate hydroxyl group to the dmso O atom of a butyrate–dirhodium complex.     

Hydrate isomerism in [Cu(en)2(H2O)1.935]2[Fe(CN)6]·4H2O

The title compound, bis[di­aqua­bis­(ethyl­enedi­amine‐κ²N,N′)copper(II)­] hexa­cyano­iron(II) tetrahydrate, [Cu(C₂H₈N₂)₂(H₂O)_1.935]₂[Fe(CN)₆]·4H₂O, was crystallized from an aqueous reaction mixture initially containing CuSO₄, K₃[Fe(CN)₆] and ethyl­enedi­amine (en) in a 3:2:6 molar ratio. Its structure is ionic and is built up of two crystallographically different cations, viz. [Cu(en)₂(H₂O)₂]²⁺ and [Cu(en)₂(H₂O)_1.87]²⁺, there being a deficiency of aqua ligands in the latter, [Fe(CN)₆]⁴⁻ anions and disordered solvent water mol­ecules. All the metal atoms lie on centres of inversion. The Cu atom is octahedrally coordinated by two chelate‐bonded en mol­ecules [mean Cu—N = 2.016 (2) Å] in the equatorial plane, and by axial aqua ligands, showing very long distances due to the Jahn–Teller effect [mean Cu—O = 2.611 (2) Å]. In one of the cations, significant underoccupation of the O‐atom site is observed, correlated with the appearance of a non‐coordinated water mol­ecule. This is interpreted as the partial contribution of a hydrate isomer. The [Fe(CN)₆]⁴⁻ anions form quite regular octahedra, with a mean Fe—C distance of 1.913 (2) Å. The dominant intermolecular interactions are cation–anion O—H⋯N hydrogen bonds and these inter­actions form layers parallel to (001).     

K2[Mo2O4(C2O4)2(H2O)2]·3H2O

The crystal and molecular structure of dipotassium di‐μ‐oxo‐bis[aqua(oxalato‐O¹,O²)oxomolybdenum(III)] trihydrate, K₂­[Mo₂O₄(C₂O₄)₂(H₂O)₂]·3H₂O, has been determined from X‐ray diffraction data. In the dimeric anion, which has approximate twofold symmetry, each Mo atom is in a distorted octahedral coordination, being bonded to one terminal oxo‐O atom, two bridging O atoms, two O atoms from the oxalato ligand and one from the water mol­ecule. Bond lengths trans to the multiple‐bonded terminal oxo ligand are larger than those in the cis position, confirming the trans influence as a generally valid rule.     

The first example of a two‐coordinated AuI atom bonded to an FeII atom and an N‐heterocyclic carbene (NHC) ligand

The aurophilicity exhibited by Au^I complexes depends strongly on the nature of the supporting ligands present and the length of the Au–element (Au—E) bond may be used as a measure of the donor–acceptor properties of the coordinated ligands. A binuclear iron–gold complex, [1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene‐2κC²]dicarbonyl‐1κ²C‐(1η⁵‐cyclopentadienyl)gold(I)iron(II)(Au—Fe) benzene trisolvate, [AuFe(C₅H₅)(C₂₇H₃₆N₂)(CO)₂]·3C₆H₆, was prepared by reaction of K[CpFe(CO)₂] (Cp is cyclopentadienyl) with (NHC)AuCl [NHC = 1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene]. In addition to the binuclear complex, the asymmetric unit contains three benzene solvent molecules. This is the first example of a two‐coordinated Au atom bonded to an Fe and a C atom of an N‐heterocyclic carbene.     

Crystallographic report: Diaquabis(1,10‐phenanthroline)zinc(II) 4,5‐dihydroxy‐1,3‐benzenedisulfonate trihydrate

The zinc atom has a distorted octahedral geometry defined by two 1,10‐phenanthroline and two cis water molecules. A three‐dimensional network structure arises owing to extensive hydrogen bonds involving all the components of [Zn(phen)₂(H₂O)₂][C₆H₂(OH)₂(SO₃)₂]·3H₂O. Copyright © 2005 John Wiley & Sons, Ltd.