Mamoru Shimoi

Fluxional behavior of chromium and tungsten complexes of monodentate bis(trimethylphosphine)diborane(4), [M(CO)5(η1-B2H4·2PMe3)] (M=Cr, W):: A model case for alkane–metal complexes

Abstract Group 6 metal complexes of monodentate bis(trimethylphosphine)diborane(4), [M(CO) 5 (η 1 -B 2 H 4 ·2PMe 3 )] (M=Cr, W) show two fluxional processes in solution: one is the very rapid exchange of the coordinated B H atom with the geminal hydrogen atom, and the other one is rather slow exchange with the vicinal hydrogens. This behavior embodies the fluxionality predicted for the tungsten ethane complex, [W(CO) 5 (η 1 -C 2 H 6 )].

Molecular structure of chlororuthenocenium +BF4− and chlorobiruthenocenium +BF4− salts

Abstract The structures of chlororuthenocenium +BF4− ([RcHCl]+BF4−, 1) and chlorobiruthenocenium +BF4− ([RcRcCl]+BF4−, 2) were determined by single-crystal X-ray diffraction studies. The crystal form of 1 is monoclinic, space group P2 1 /c, a = 7.801(6), b = 14.370(6), c = 10.422(3) A , β=91.91(4)°, Z=4, with the final R=0.032 and Rw=0.038 . The cyclopentadienyl (Cp) rings in the cation are slanted greatly (dihedral angle, 34.54 °) according to the RuIVCl bond (2.417(2) A) formation. The crystal form of 2 is monoclinic, space group P2 1/n , a=24.539(4), b=10.627(5), c=7.333(4) A , β=93.57(3)°, Z=4, with the final R=0.044 and Rw = 0.033 . The cation formulated as [RuIICp(C5H4C5H4)CpRuIVCl]+ exists in a trans-conformation, as in the case of neutra biruthenocene (RcRc). The distance between the RuII and RuIV (5.366(1) A) indicates the absence of metal-metal interaction. The Cp and C5H4 planes in the [Cp(C5H4)RuCl]+ moiety are more slanted (dihedral angle, 39.98°) than that of 1. Moreover, the fulvalence ligand (C5H4C5H4) is not planar owing to the repulsion between the two Cl and the C1 atoms which connect the two C5H4 moieties.

Crystal and molecular structures of bis[2-(2-benzoxazolyl)phenol-N]dichloropalladium(II)

Abstract The crystal and molecular structure of bis[2-(2-benzoxazolyl)phenol-N]dichloropalladium(II), was determined by the single-crystal X-ray diffraction. The palladium atom is at the symmetry centre in a square-planar geometry, where two 2-(2-benzoxazolyl)phenol (Hbxp) molecules are coordinated with their N atoms as unidentate ligands in the trans position.

Molecular structure of iodo [1.1]ferrocenylruthenocenophanium+ BF4− salt

Abstract The structure of iodo[1.1]ferrocenylruthenocenophanium+ BF4− (1), prepared by oxidation of [1.1]ferrocenylruthenocenophane ([1.1])FcRc) with iodoruthenocenium+ BF4− ([RcHI]+ BF4−) was analyzed by single-crystal X-ray diffraction. The crystal form of 1 is triclinic, space group P 1 , a = 9.794( 2 ), b = 14.393( 4 ), c = 7.777(2) A , α = 101.62(4), β = 93.17(4), γ = 72.09(2)°, Z = 2 , and the final R and Rw were both 0.052. The cation exists in a syn-conformation, as with other [1.1]metallocenophanes, and is given the formula [Fe(II)(C5H4CH2C5H4)2Ru(IV)I]+ with Ru(IV)-I bond (2.751(1) A) formation in the solid. The distance between the Ru(IV) and Fe(II) atoms is 4.719(1) A, which is slightly shorter than the value for [1.1]FcRc, and the bond angle of IRu(IV)Fe(II) is 91.50(1)°. The cation has two kinds of twisted C5H4CH2C5H4 systems. The cyclopentadienyl rings in the [Cp(C5H4)RuI]+ moiety are highly slanted (the dihedral angle between the Cp ring and fulvenide ligand is 33.87°) owing to the Ru(IV)-I bond. Large downfield shifts of the 13C CP/MAS NMR signals for the ruthenocene moiety are explained by the same fact.