R. Ugo

Zerovalent platinum chemistry. III Properties of Bistriphenylphosphineplatinum(0)

Abstract The cordinative reactivity and stability of the species Pt(PPH 3 ) 2 are reported; its reactivity towards small molecules is compared with that of a chemisorption center on a metal surface. The relation between the coordinative unsaturation and chemical behaviour of Pt(PPH 3 ) 2 and the carbenoid character for the platinum atom is discussed.

Zerovalent platinum chemistry. VIII. The reactions of nitric oxide with tris- and tetrakis (triphenylphosphine) platinum(0)☆

Abstract The lemon-yellow complex obtained on reacting tris-or tetrakis (triphenylphosphine)platinum(0) with nitric oxide under anaerobic conditions is formulated as a monomeric hyponitrite derivative of platinum(II), Pt(N2O2)(PPh3)2, on the basis of chemical and spectroscopic evidence. Attempts to prepare the previously reported «binuclear nitric oxide complexes of palladium and platinum» were unsuccessful.

Zerovalent platinum chemistry. Part VI. The reactions of bis- and tris-triphenylphosphineplatinum(0) with hydrogen sulphide, hydrogen selenide, sulphur, and related molecules

The reactions of Pt(PPh3)n(n= 2 or 3) with H2M, HMPh, and M (M = S or Se) to form adducts have been studied. The reactivity of the products towards soft and hard reagents has been investigated and compared with that of related H2M, HMPh, and M adducts of some RhI and IrI triphenylphosphine complexes. The results agree with the proposed mechanisms of poisoning of metal surfaces by species such as H2M or M.

Zerovalent platinum chemistry. Part IV. Bistriphenylphosphineplatinum(0) complexes with some activated mono-olefins and monoalkynes

Compounds of formula [Pt(PPh3)2L](where L is an activated mono-olefin or monoalkyne) have been obtained by the direct interaction of Pt(PPh3)n(n= 2 or 3) or [Pt(PPh3)2(CH2:CH2)] with the activated ligands.The bonding between the platinum atom and the unsaturated ligands has been studied by a comparison of the stabilities of the adducts and on examination of the principal features of the i.r. and 1H n.m.r. spectra.

Zerovalent platinum chemistry. Part V. Bistriphenylphosphineplatinum(0) quinone complexes

Compounds of formula [Pt(PPh3)2(quinone)] where the quinone is 1,4-benzoquinone, 2,3,5,6-tetrachloro-1,4-benzoquinone-1,4-naphthoquinone, 3,4,5,6-tetrachloro-1,2-benzoquinone, 1,2-naphthoquinone, and 9,10-phenanthrenequinone have been synthetised. With 2,3,5,6-tetramethyl-1,4-benzoquinone a compound of formula {Pt(PPh3)2}2(quinone) has been obtained. The type of bonding and the factors influencing the strength of the bond between Pt(PPh3)2 and the quinone moiety have been discussed on the basis of i.r., 1H n.m.r. and electronic spectra.

Zerovalent platinum chemistry. Part VII. Oxidative addition of diazonium salts to triphenylphosphine derivatives of platinum(0)

Compounds of formula [(PPh3)3PtN:N·C6H4R-p]+(X–)(R = NO2, F, H, OMe, Me and X = BF4; R = NMe2, NEt2 and X = BPh4) have been obtained by interaction of Pt(PPh3)3 with diazonium salts. Similar derivatives could not be isolated by allowing [Pt(PPh3)2L](L = CH2:CH2, CH2:CHCN) to react with diazonium salts. The reactivity of the platinum–azo-compounds towards H2, O2, HX (X = Cl–, BF4–, ClO4–) and LiX (X = Cl–, I–, N3–) has been studied and rearrangements caused by solvents or light have also been investigated. I.r., 1H n.m.r. and electronic spectra are reported and discussed.