L. N. Zakharov

Synthesis and characterization of the lutetium naphthalene complex, CpLuC10H8(DME)

Abstract The title compound ( 1 ) was obtained as black diamagnetic crystals by reaction of CpLuCl 2 with sodium naphthalide in DME. The naphthalene moiety in 1 is bent about the C(1)⋯C(4) plane (dihedral angle 148.5°). The LuC(C 10 H 8 ) bond lengths and redistribution of CC bond distances in the coordinated naphthalene ring suggest 2η 1 :η 2 -interaction of the Lu atom with the naphthalene moiety.

Synthesis and structure of bis(triphenylgermane)tetrakis(tetrahydrofuran)ytterbium

Abstract The reaction of the naphthalene complex of ytterbium C 10 H 8 Yb(THF) 3 with dihydrogen under ambient conditions gives the ytterbium dihydride [H 2 Yb(THF)] n . The reaction of the naphthaleneytterbium with Ph 3 GeH in THF at room temperature gives the unusual germaneytterbium complex (Ph 3 GeH) 2 Yb(THF) 4 . An X-ray diffraction study ( a = 9.980(2), b = 17.305(4), c = 13.883(3) A, β = 96.37(2)°, Z = 2, space group P 2 1 , 4552 reflections, R = 0.036, R w = 0.031) has shown that the Yb atom in the molecule of this complex has octahedral coordination; the four THF molecules are in the equatorial plane and the Ph 3 GeH ligands are in the axial positions. The hydride H atoms of the Ph 3 GeH groups form μ 2 -bridges between Yb and Ge atoms.

Synthesis and structure of a compound with an ytterbiumtin bond, (Ph3Sn)2Yb(THF)4

Abstract The distannylytterbium complex (Ph 3 Sn) 2 Yb(THF) 4 was obtained by reaction of naphthaleneytterbium with Ph 4 Sn. According to X-ray data this molecule has a distorted octahedral structure. The Yb atom is bonded with four oxygen atoms of THF molecules which are on the equatorial plane and with two Sn atoms of Ph 3 Sn groups in axial positions. The SnYb distances are equal 3.305(1) A, the SnYbSn angle is 164.5(1)°. Crystals are monoclinic with space group C 2/ c and unit cell dimensions a 16.190(3), b 15.903(3), c 19.066(4) A, ° 98.91(3)°, Z 4, D c 1.59 g cm −3 . The same complex was obtained in low yield in the reaction of naphthaleneytterbium with Ph 6 Sn 2 . Tetraphenylgermane does not react with C 10 H 8 Yb(THF) x .

Some peculiarities of structure, stability and reactivity of compounds containing metal—metal bonds

Abstract The complete X-ray analysis of bis(triphenylgermyl)mercury has been carried out. HgGe bond lengths in the well-known structures of bi- and polynuclear organometallic compounds are shown to be covalent and change over a wide range. The influence of screening efficiency of central metal atom in bi- and polyorganometallic compounds upon their reactivity and thermal stability has been treated.

The interaction of nickelocene with bis(triphenylgermyl)cadmium

Abstract The reaction of bis(triphenylgermyl)cadmium with nickelocene proceeds through the displacement of a cyclopentadienyl ring and the formation of an organopolymetallic compound containing nine metal atoms: This is a new type of organometallic compound, containing NiCd bonds.

NOVEL POLYNUCLEAR ORGANOTIN COMPLEXES OF SAMARIUM AND YTTERBIUM

Abstract Polynuclear complexes [(Me 3 Sn) 3 Sn] 2 Ln(THF) 4 (Ln  Sm ( 1 ), Yb ( 2 )) have been synthesized by reacting Me 3 SnCl with samarium or ytterbium in THF. The crystals of 1 and 2 are orthorhombic ( a = 21.511(2), b = 13.215(3), c = 20.640(4) A, Z = 4, space group Pca 2 1 for Ln  Sm and a = 21.534(3), b = 13.158(2), c = 20.616 A, Z = 4, space group Pca 2 1 for Ln  Yb). A similar organotin complex of ytterbium, [(Me 3 Sn) 3 Sn] 2 Yb(THF) 4 ( 3 ) having the same composition but different structure than compound 2 has been isolated from the reaction of MeSnCl 3 with Yb. The crystals of the compound 3 are tetragonal, a = 20.851(4), c = 26.311(5) A, Z = 8, space group I 4 2 d . In all cases the molecules of [(Me 3 Sn) 3 Sn] 2 Ln(THF) 4 have a distorted octahedral structure in which the central Ln (Ln  Sm, Yb) atom is bonded to four oxygen atoms of THF molecules in equatorial positions and two tin atoms of (Me 3 Sn) 3 Sn groups in axial positions. The molecule of 3 has a C 2 symmetry and an approximately eclipsed arrangement of (Me 3 Sn) 3 Sn groups. The Yb-Sn distance is 3.300(4) A. The molecules of 1 and 2 have a staggered arrangement of the (Me 3 Sn) 3 Sn groups with Ln-Sn distances of 3.402(4), and 3.386(4) A for Ln  Sm, and 3.289(5) and 3.299(4) A for Ln  Yb.

Synthesis and structure of a polynuclear complex with a framework consisting of germanium, bismuth and platinum atoms

Abstract The structure of the product of the interaction of (C6F5)2GeH2 with Et3Bi has been defined more precisely by X-ray analysis. The heteroelemental framework of this compound is found to be a trigonal bipyramid in which the two apical Bi atoms by three bis(pentafluorophenyl)germyl bridges. The symmetry of the framework isD3h. The average value of the GeBi bond length is 2.739(1) A. The average values of the GeBiGe and BiGeBi angles are equal to 72.11(4) and 93.94(4)°, respectively. Reaction of the compound with Pt(PPh3)3 yields the unusual 6-nuclear complex [(C6F5)2Ge]3Bi2Pt(PPh3)2. It was shown by an X-ray study that the two Ge, two Bi and Pt atoms form a nonplanar cycle in this complex. Moreover, the Bi atoms are bonded by the (C6F5)2 bridged group. The symmetry of the heavy atom framework is somewhat disordered from Cs. The Pt atom has a square-planar coordination. The GePt and BiPt lengths are equal to 2.466(3) and 2.759(3) A, respectively. The GeBi bond lengths are changed in the range from 2.695(5) to 2.774(6) A depending on their positions in the molecule. The GeBiGe angles in the 4-member GeBiGeBi cycle are 87.6(2) and 70.9(2)°, and the BiGeBi angles are 98.3(2) and 98.5(2)°. The GeBiGe angle in the 5-member PtGeBiGeBi cycle is equal to 87.6(2)°, and the GeBiPt angle is 100.8(1)°. The pentafluorophenyl and triphenylphosphine ligands have the usual geometry.

Synthesis and structure of organosilicon and organogermanium complexes of ytterbium (Ph3E)2Yb(THF)4 with YbSi and YbGe bonds

Abstract Complexes (Ph 3 Si) 2 Yb(THF) 4 ( 1 ) and (Ph 3 Ge) 2 Yb(THF) 4 ( 2 ) were synthesised by the reactions of Ph 3 SiCl or Ph 3 GeCl with ytterbium in THF and characterised by X-ray diffraction. Compounds 1 and 2 have similar centrosymmetrical octahedral structures with a central Yb atom bonded to four oxygen atoms of THF molecules in equatorial positions and two Si (or Ge) atoms of SiPh 3 (or GePh 3 ) fragments in axial positions. In the crystal of 2 there are two symmetrically independent molecules with the same structure. The YbSi and YbGe distances in 1 and 2 are 3.158(2) and 3.170(2), 3.141(2) A, respectively.

Synthesis and structures of the six-coordinate donor-acceptor complexes R3(C6H4O2)Sb…L (R=Ph, L=OSMe2 or ONC5H5; R=Me, L=ONC5H5 or NC5H5) and R3(C2H4O2)Sb…L (R=Ph, L=ONC5H5; R=Cl or C6F5, L=OPPh3)

One-pot oxidation of R3Sb (R=Ph, Me, Cl, or C6F5) withtert-butyl hydroperoxide in the presence of 1,2-diols and monodentate donor compounds was studied. The structures of the resulting neutral organic donor-acceptor SbV complexes, Ph3(C6H4O2)Sb…OSMe2, Ph3(C6H4O2)Sb…ONC5H5, Me3(C6H4O2)Sb…ONC5H5, Me3(C6H4O2)Sb…NC5H5, Ph3(C2H4O2)Sb…ONC5H5, and Cl(C6F5)2(C2H4O2)Sb…OPPh3, were established by X-ray diffraction analysis. In these complexes, the coordination environment about the Sb atoms is a distorted octahedron. The Sb−O(N) distances and the Sb−O−E angles (E=S, N, or P) vary over wide ranges.

FERROUS TRIS( TRIMETHYLSILYL) SILANOLATES : SYNTHESIS, STRUCTURE, REACTIVITY AND THERMAL DECOMPOSITION

Abstract Reaction of FeBr2 with 3 equiv. of sodium tris(trimethylsilyl)silanolate (1) in DME affords the ate-complex {(Me3Si)3SiOFe[μ-OSi(SiMe3)]2Na(DME)} (2). X-ray studies have shown the Fe atom in 2 is bonded to three O atoms of OSi(SiMe3)3 groups, two O atoms are connecting as a μ-bridge the Fe[OSi(SiMe3)3]3] unit with the Na(DME) group. The FeO3 core is slightly non-planar: the deviation of the Fe atom from the O3 plane is 0.08A. The four-member Fe(μ-O)2Na cycle is also non-planar: the dihedral angle between the Fe(μ-O)2 and the (μ-O)2Na planes is 31.0°. The bridging and terminal FeO distances are 1.840(2) and 1.894(2), 1.910(2) A, respectively. The average SiSi and SiC distances are 2.358(8) A and 1.873(8) A. Interaction of FeBr2 with two equiv. of 1 in THF followed by treatment with pyridine yields the adduct, [(Me3Si)3SiO]2Fe(Py)2 (3). The Mossbauer spectrum of complex 2 at 295 K consists of a single doublet with isomer shift 0.60(1) mm/s and quadrupole splitting 0.90(3) mm/s. The corresponding parameters of 3 are as follows: isomer shift, 1.08(1) mm/s, and quadrupole splitting, 2.12(2) mm/s. Molecular oxygen is easily incorporated into the SiSi bonds of compounds 2 and 3 by activation at the iron (II) center. Reaction of 2 with 1 equiv. of tetracyanoethylene leads to iron (III) silanolate, [(Me3Si)3SiO]3Fe (4) and the anion-radical salt, Na +TCNE−. Slow thermolysis of 2 and 3 yields (Me3Si)2SiOSiMe3 and (Me3Si)4Si as well as polyferrsiloxane with MW ∼ 3500. Fast thermolysis results in formation of α-Fe and a complicated mixture of oligosiloxanes.