Piotr A. Kibala

Reactions of M-M bonded dinuclear zirconium(III) complexes with vicinal dihaloalkanes and olefins: a new type of metal-olefin complex

Abstract The reaction of Zr2X6(PR3)4 compounds with vic-dihalides or with olefins gives Zr2X6(PR3)4(C2R4) compounds in which the mid-point of the olefin lies between the two Zr atoms, providing an unprecedented type of metal—olefin complex.

Preparation and structural characterization of Rh2(O2CCPh3)4(EtOH)2, Ru2(O2CCPh3)4(H2O)(EtOH).2EtOH and Mo2(O2CCPh3)4.3CH2Cl2

Abstract Triphenylacetic acid and its sodium salt were used in the preparation of three dimetal tetracarboxylates. The reaction of RhCl 3 with NaO 2 CCPh 3 in ethanol gives Rh 2 (O 2 CCPh 3 ) 4 (EtOH) 2 ( 1 ). The exchange reaction of Mo 2 (O 2 CCH 3 ) 4 with NaO 2 CCPh 3 in dichloromethane yields Mo 2 (O 2 CCPh 3 ) 4 ·3CH 2 Cl 2 ( 2 ). The reaction of Ru 2 [ l -O 2 CCH(OH)Ph] 4 (H 2 O) 2 with HO 2 CCPh 3 in ethanol results in Ru 2 (O 2 CCPh 3 ) 4 (H 2 O)(EtOH)·2EtOH ( 3 ). The structures of these compounds were determined by single crystal X-ray crystallography. The crystallographic data for 1 are as follows: tetragonal, space group I 4 with unit cell dimensions a = b =18.340(2), c =10.646(1) A, V =3581.1(6) A 3 , Z =2. The structure was refined to R =0.053 ( R w =0.059) with 1431 reflections having I >3σ( I ). The RhRh distance is 2.365(1) A, RhO(1)=1.967(6) A, RhO(2)=2.047(6) A, RhO(axial)=2.31(2) A. The pertinent crystallographic data for 2 are as follows: tetragonal, space group P 4/ ncc with unit cell dimensions a = b =20.930(4), c =17.404(4) A, V =7624(5) A 3 , Z =4. The structure was refined to R =0.048 ( R w =0.064) with 1269 reflections having I >3σ( I ). The MoMo distance is 2.076(1) A, MoO(1)=2.098(5) A, MoO(2)=2.095(6) A. The crystallographic data for 3 are as follows: monoclinic, space group C 2/ c with unit cell dimensions a =19.872(7), b =16.985(6), c =23.36(1) A, β=94.24(3)°, V =7864(5) A 3 , Z =4. The structure was refined to R =0.063 ( R w =0.094) with 2893 reflections having I >3σ( I ). The RuRu distance is 2.252(2) A; the RuO distances are 2.079(7), 2.061(8), 2.073(7) and 2.064(7) A; the RuO(axial) distances are both 2.35(1) A. The Mo atoms of 2 do not experience any axial interactions, and there is a resulting decrease of 0.016 A in the MoMo quadruple bond distance compared to Mo 2 (O 2 CR) 4 molecules having axial coordination.

Three new dicarboxylatodirhenium(III) compounds and their structures: a structure type not previously seen

Three new structures of compounds containing the Re 2 (O 2 CR) 2 X 4 unit are reported and two are shown to contain features rarely or not previously observed. Reaction of trimeric ReCl 3 and PhCOONa in THF under reflux conditions for 24 h gave dark-green orthorhombic crystals of the THF solvate cis -Re 2 (O 2 CPh) 2 Cl 4 (THF) 2 ·THF ( 1 ). The crystals belong to the space group Pbcm with unit cell dimensions a = 8.867(2), b = 19.851(4), c = 18.022(4) A, V = 3172(2) A 3 , and D calc = 2.037 g/cm 3 for Z = 4. The structure was refined to R = 0.037 and R w = 0.046 for 1825 reflections having I >3σ( I ). Reaction of [(n-C 4 H 9 ) 4 N] 2 Re 2 Cl 8 and NaF in acetonitrile under reflux conditions for 4 days followed by work-up in acetone gave blue, monoclinic crystals of cis -[(n-C 4 H 9 ) 4 N][Re 2 (O 2 CCH 3 )Cl 5 ]· (CH 3 ) 2 CO ( 2 ).The crystals belong to the space group P 2 1 / n with unit cell dimensions a = 11.283(4), b = 13.577(5), c = 21.835(10) A, V = 3345(4) A 3 , and D calc = 1.923 g/cm 3 for Z = 4. The structure was refined to R = 0.056 and R w = 0.066 for 2443 reflections having I >3σ( I ). Compound 3 , [ReCl 2 (dpcp) 2 ][Re 2 (O 2 CPh) 2 Cl 6 ]·CHCl 3 contains the first example of an axially coordinated species with a transoid arrangement of the carboxylate ligands. 3 crystallizes in space group P with a = 13.372(4), b = 14.067(6), c = 10.899(7) A, α = 99.694(5)°, β = 103.030(5)°, γ = 84.501(3)°, V = 1966(3) A 3 , Z = 1. The structure was refined to R = 0.067 and R w = 0.082 for 2648 reflections with I >3σ( I ).

Synthesis and molecular structure of the first discrete rhenium polysulphide complex, (n-Bu4N)[ReS9]

Abstract (n-Bu4n)[Re(S4)2S] has been prepared by reacting (n-Bu4N2)[Re2Cl8] with Li2S5 in THF. It crystallizes in the monoclinic space group P21/n with the following unit cell constants: a = 11.215(3) A, b = 14.910(7) A, c = 16.654(4) A, β = 91.47 (2)°, V = 2783(3) A3, Z = 4. The anion is the first mononuclear rhenium complex containing ReSx chelate rings that has been isolated and structurally characterized. The [ReS9]− anion consists of two chelating S4− chains and a ReS unit. The geometry around the Re atom is best described as a tetragonal pyramid with the metal atom displaced towards the centre of the pyramid. The ReS bond length is 2.075(4) A and the average ReS bond length is 2.30[2] A.

Square, sulphur-bicapped tetraniobium cluster compounds

Abstract By addition of first PhSSPh and then PMe2R (R = Ph, Me) to a solution of NbCl5 that has been reduced with Na/Hg, the orange, crystalline compounds Nb4S2(SPh)8(PMe2Ph)4·C7H8 (1) and Nb4S2(SPh)8(PMe3)4·C7H8·C4H8O (2) are obtained. They are closely related to the [Nb4S2(SPh)12]4− anion previously reported by Christou and co-workers (L. Seela, J. C. Huffman and G. Christou, J. Chem. Soc., Chem. Commun. 1987, 1258). In each compound four niobium and two sulphur atoms form a tetragonal bipyramid with sulphur atoms at the apices. The mean NbNb and NbSap distances are, respectively, 2.816(8) and 2.491(3) A, for 1 and 2.812(6) and 2.404(3) A for 2. Each NbNb bond (postulated to be single) is bridged by two SPh groups (mean NbSbbr distances for 1 and 2 are 2.624(8) and 2.626(3) A, respectively) and there is a phosphine ligand coordinated to each niobium atom (mean NbP distances for 1 and 2 are 2.706(1) and 2.677(4) A, respectively). Compound 1 crystallizes in triclinic space group P 1 with unit cell dimensions: a = 13.411(6), b = 14.588(4), c = 13.058(5) A, α = 98.05(3), β = 114.95(3), γ = 66.35(3)°, V = 2210(2) A3 and dcalc = 1.530 for Z = 1. The structure was refined to R = 0.0439 and Rw = 0.0590 for 4740 reflections with I > 3σ(I). Compound 2 crystallizes in monoclinic space group C2/m with unit cell dimensions: a = 19.333(10), b = 19.965(8), c = 12.048(5) A, β = 120.00(4)°, V = 4027(7) A3 and dcalc = 1.466 for Z = 2. The structure was refined to R = 0.0547 and Rw = 0.0674 for 1480 reflections having I > 3σ(I).