Hikaru Ichida

A novel mode of generation and stereospecific cis-[2+2]cycloaddition of an overcrowded germanethione

Abstract Desulfurization or thermal decomposition of overcrowded 1,2,3,4,5-tetrathiagermolane 2 resulted in the formation of novel folded dithiadigermetane 3 via stereospecific [2+2]cycloaddition of intermediary germanethione 1 bearing two different bulky substituents.

A notice: incorrect formulation in the synthetic method of 2,2′-bis(diphenylphosphino)biphenyl

Abstract The reaction of 2,2′-dilithiobiphenyl with chlorodiphenylphosphine gives a mixture of triphenylphosphine and 5-phenyldibenzophosphole in almost equal quantities. The formation of the latter phosphine was confirmed by X-ray diffraction study of its platinum(II) derivative. The 31P and 13C NMR data also support the formulation of this reaction. All these experimental facts together clearly demonstrate that the previously reported synthetic method of 2,2′-bis(diphenylphosphino)-biphenyl was erroneously formulated.

Preparation and X-ray crystal structure of [N(CH3)4]4[{H(SO4)W3O7(O2)2}2O]

The title peroxotungstosulphate as the first example of a polytungstosulphate has been prepared and its structure determined. The salt crystallizes under the conditions: [WO 4 2− ]=0.3−1.0 mol dm −3 , [WO 4 2− ]/[SO 4 2− ]=1−1/4, [WO 4 2− ]/[H 2 O 2 ]=1/2−1/4 and pH<1. The SO 4 2− tetrahedron shares its three vertices with two WO 5 (O 2 ) 2 decahedra and one WO 6 octahedron to form a diperoxotritungstosulphate moiety; the polyanion is made of the two moieties bridged with three μ-oxo groups

Equilibria of the H+-MoO42−-SeO32− system in aqueous 1 M Na(Cl) medium

The equilibria pH+ + qMoO42− +rSeO32− ⇌ (H+)p(MoO42−q(SeO32−)r have been investigated by potentiometry at 25°C in 1 M Na(Cl). The data have been explained by the formation of the following ternary species denoted by (p,q,r) according to the equation above: (10,5,2), (11,5,2), (14,8,2) and (15,8,2). 77Se NMR spectra have also been recorded at various hydrogen ion concentrations.

PREPARATION AND STRUCTURE OF TETRAMETHYLAMMONIUM HYDROGEN TRIPEROXOTRIMOLYBDODISULFATE TRIHYDRATE, [N(CH3)4]3[H(SO4)2-(MoO2(O2))3]· 3H2O

Abstract A novel peroxopolyoxomolybdate compound, [N(CH3)4]3 [H(SO4)2 (MoO2(O2))3] · 3H2O, has been obtained from a strongly acidic aqueous solution of a molybdate-sulfate system as the monoclinic crystal of P2/n, a = 13.497(3), b = 15.231(4), c = 32.603(2) A, β = 103.113(9)°, and V = 6577(2) A3. The final R-value was 0.0986 for 395 parameters using 7162 reflections. Each of the two crystallographically independent polyanions contains three molybdenum atoms with five O2−, one O2 2−, and two sulfate groups, one of which is a tripod ligand apical to the molybdenum plane, and the other is a bipod ligand equatorial to the Mo plane.

IR, Raman and 13C NMR spectra of peroxotungstooxalate

The present authors have recently reported that tungsten carbide (WC) reacts with dilute hydrogen peroxide to give a yellow glassy peroxotungstate containing carbon (CWHPA). We have investigated the H + -WO 4 2− -C 2 O 4 2− -H 2 O 2 sytems spectroscopically in order to explain the relationship between the crystal structure and the behavior of CWHPA in solution