Vivien C. Yee

(η5-Cyclopentadienyl)oxo(peroxo-O,O')(trimethylsilylmethyl)tungsten and the Related (η5-Pentamethylcyclopentadienyl)oxo(peroxo-O,O')(trimethylsilylmethyl)tungsten-Tetracyanoethylene (2/1)Complex

The two organometallic molecules, [WO(C 5 H 5 )(C 4 H 11 Si)(O 2 )] and [WO(C 10 H 15 )(C 4 H 11 Si)(O 2 )] [2 :1 complex with C 6 N 4 (TCNE, ethenetetracarbonitrile)], have similar piano-stool structures and separate oxo and peroxo ligands [W-O(oxo) = 1.69(3) and 1.727(7), W-O(peroxo) = 1.91 (mean), O-O = 1.43(3) and 1.426(11)A]. The 2 :1 complex contains a TCNE molecule disordered over two sites, sandwiched between two organometallic molecules, with O(peroxo)...C(TCNE) distances of 2.94(2)-3.33 (2) A (the asymmetric unit is one Cp * W molecule and half of a TCNE molecule disordered over two sites).

α-Naphthyl Phenyl Pinacols

Treatment of α-naphthyl phenyl ketone with Zn/acetic acid gives racemic α-naphthyl phenyl pinacol [1,2-di(1-naphthyl)-1,2-diphenylethane-1,2-diol], C 34 H 26 O 2 , but reaction with Mg/MgI 2 gives a product which proves to be not a pinacol, but a tricyclic compound (with four chiral centers, formed by addition at the 2-position of one of the naphthalene groups), racemic 5-(1-naphthyl)-3,5-diphenyl-4-oxatricyclo[7.4.0.0 2,6 ]trideca-7,9,11,13-tetraen-3-ol, C 34 H 26 O 2 . The aromatic ring in this tricyclic compound is planar, but the other six-membered ring, and the five-membered furano ring, are non-planar. Bond lengths and angles in both molecules correspond to the molecular formulations. In both structures, the OH groups are involved in only weak intermolecular interactions.

(η5-Cyclopentadienyl)[2-(1,1-diphenylethyl-C2)phenyl-C1[oxo(trimethylsilylmethylthio)tungsten, [WO(C4H11SSi)(C5H5)(C20H16)]

Treatment of [CpW(NO)(CH 2 SiMe 3 )(CH 2 CPh 3 )] with sulfur produces [CpW(O)(SCH 2 SiMe 3 )(CH 2 CPh 2 C 6 H 4 )], in which S is inserted in one W−C bond, but in addition, replacement of NO by O and orthometallation have occurred

Structure of a mixed crystal of α- and β-pipitzol (1:1), C15H20O3.C15H20O3

The structure of a mixed crystal (1:1, space group P1) of α- and β-pipitzol {[3R-(3α,3aβ,7β,8aα)]- and [3R-(3α,3aα,7α,8aβ)]-1,2,3,7,8,8a-hexahydro-5-hydroxy-3,6,8,8-tetramethyl-4H-3a,7-methanoazulene-4,9-dione} is described. The two molecules are enantiomeric at three C centres, but have the same (R) configuration at one C atom and are linked into α/β pairs about pseudo centres of symmetry by O-H...O hydrogen bonds

Structure of dimethyl 9-chloro-9,10-dihydro-9,10-ethenoanthracene-11,12-dicarboxylate

The two ester groups five different orientations, with C=C-C=O torsion angles of -165.7(3) and -89.4(4) o respectively for the groups remote from and adjacent to the Cl substituent. The remote ester group is therefore fully conjugated with the C=C double bond [cos 2 (angle)=0.94] and the adjacent group non-conjugated [cos 2 (angle)=0], presumably as a result of steric effects