F. Glockling

A MASS SPECTROSCOPIC STUDY OF ORGANOMERCURIALS AND MERCURIC HALIDES

Abstract The fragmentation of various mercury compounds of the types HgR2, HgXR and HgX2 is reported where R = Me, C6H5, mFC6H4, p-FC6H4, Me3MCH2 (M = Si, Ge) and X = halide. Their behaviour, especially that of the organomercury halides, varies considerably with the nature of the R group whilst changing the halide has little effect. For diarylmercurials and arylmercuric halides the base peak is the carbonium ion R+ whereas in the methylmercury halides the base peak is HgXMe+·. In compounds containing the grouping Me3MCH2Hg the fragmentation is dominated by cleavage of the MeM rather than HgC bonds. For the mercury(II) dihalides variations in electron voltage give evidence for two routes to the X+ ion. Attempts to prepare (o-FC6H4)2Hg resulted in the isolation of 2, 2′-(o-fluorophenyl)diphenylmercury. Some ionization and appearance potentials are reported.

Tris(trimethylsilyl)methyl-lead(IV) compounds

Abstract PbMe 3 [C(SiMe 3 ) 3 ] may be mono- or di-halogenated to PbXMe 2 R or PbX 2 MeR (R = (Me 3 Si) 3 C, X = Cl, Br) without cleavage of the RPb bond. Similarly electrophilic cleavage of one PbMe bond occurs selectively when PbMe 3 R is treated with acetic or halosubstituted acetic acids yielding monoesters. The esters, PbMe 2 R(OCOCX 3 ) slowly decomposed in solution to PbXMe 2 R + CO 2 + CX 2 . The formate ester PbMe 2 R(OCHO) appeared to disproportionate in benzene solution to PbMe 3 R and products derived from PbMeR(OCHO) 2 ( viz. Pb + Pb(OCHO) 2 + CO 2 + RH + CH 4 ). Other esters also disproportionated to PbMe 3 R when heated in aqueous dioxan.

Some group IVb complexes of iridium

Abstract Trans -(Ph 3 P) 2 (CO)ClIr (I) adds HSiCl 3 , HGeCl 3 and Me 3 SiH yielding dihydridoiridium complex (Ph 3 P) 2 (R 3 M)(CO)(H) 2 Ir (II). Exchange reactions between (II), (R 3 M = Me 3 Ge) and silanes and stannanes favour reaction products in the order: Cl 3 Si>Bu 3 Sn∼Me 3 Sn>Me 3 Ge>Me 3 Si and Cl 3 Ge>Me 3 Ge. A possible mechanism for these exchange reactions is discussed. Complex (II) hydrogenates hex- 2 -yne to hex- 2 -ene.

A mass spectroscopic study of platinum alkyl and aryl complexes

Abstract A mass spectroscopic study is reported on compounds of the type PtR2L2 where L = PR3 or L2 = a chelating diphosphine and R = alkyl or aryl. Various factors affecting fragmentation paths and ion abundances have been identified. Rearrangement processes occur in which organic groups are transferred to and from P and Pt, and a mechanism is proposed whereby polyphenyl ions are formed. The thermal decomposition of PtAr2(PPh3)2 (Ar = Ph, m- and p-FC6H4) produces at 110–150°C yellow or red platinum cluster compounds.

Electron impact determination of heats of formation and bonds energies in triphenyltin compounds

Abstract Heats of formation and bond dissociation energies for various triphenyltin compounds Ph 3 SnR (R= Me, Et, Ph, I, SPh, Me 3 Ge, Me 3 Sn, Ph 3 Sn) have been evaluated from appearance potential measurements

The reactivity of magnesium-dimethyl and -diphenyl towards platinum(II) halide complexes

Abstract Magnesium-dimethyl and -diphenyl are as reactive as organolithium compounds towards PtCl2L2 complexes (L = mono- or L2 = bi-dentate tertiary phosphine) and yield PtR2L2 rapidly at 20° in tetrahydrofuran. Evidence is presented for the existence of equilibria between PtR2L2 and MgR′2 or Grignard reagents, and the mixed complex PtMePhL2 is readily prepared from PtClPhL2 and MgMe2.

β-diketone derivatives of methylmercury

Abstract Compounds of the types McHg(diketonate), (Me Hg) 2 (diketonate) and McHg(amine)(diketonate) have been isolated either by direct reaction between dimethylmercury and the diketone or from the diketone and McHgN(SiMe 3 ) 2 . 1 Pyrolysis of (MeHg) 2 (C 5 H 6 O 2 ) gives Me 2 Hg and (MeHgC 5 H 6 O 2 ) 2 Hg. Complexes are mixtures of McHgC and McHgO bonded forms having complex 1 H nmr spectra. Complexation of methylmercury with β-diketones does not result in a facile demethylation reaction.