The mass spectra of a series of metal acetylacetonates have been rationalized in terms of ion reactions. There are many examples of a unit change in the valency of the metal atom of an ion with consequent reversal of the ion's odd- or even-electron character which influences the nature of its dissociation reactions. Occurrence or non-occurrence of change in valency correlates well with the established chemistry of the metals. Among the many reactions discussed are successive losses of two free radicals, and methyl and (with Fe(bzac)3) phenyl radical migrations. Many of the compounds give polymeric structures in the ionized vapour, and the existence of Ca3(acac)6 and possibly Ca2(acac)4 in the un-ionized vapour of the calcium complex is indicated by, inter alia, study of negative-ion mass spectra.
The geminal interproton coupling constants J(H-C-H) were obtained from the n.m.r. spectra of suitably deuterated compounds Me,X where X = C, Ge, Sn, Pb, 0 , S, I, N, and Li. The relation between the magnitudes of J(H-C-H), J(13C-H), and electronegativity of X in this series is explored and some correlations are proposed. The data for methyllithium do not fit with the remainder of the results. I t is tentatively concluded that in this series of compounds J(H-C-H) is a periodic property.Geminal interproton spin-spin coupling across an sp3-hybridized carbon atom has been subject to a number of theoretical investigationsl-5 and large number of data have been compiled and rationalized.6-Q I t is well established and theoretically justified that one of the important factors influencing the magnitude of J(H-C-H) is the orientation of substituents, particularly of lone pairs and the p-orbitals of double bonds, with respect to the C-H bonds. For this reason, a suitable group of compounds, for the purpose of investigating other factors, are the series Me,X where conformational considerations are likely to be least important. The data available in the literature, for X being an element, are confined to the methyl halides10 and methane.11 In a preliminary study12 we have obtained the geminal coupling con-
The work described in the present paper, which was undertaken in the course of investigations into the mass spectra of coal and coal fractions, led the author to propose mechanisms of dissociation and rearrangement reactions of ions derived from benzyl alcohol and from o-, m-, and p-hydroxybenzyl alcohol on the basis of a study of :(i) the mass spectra of these latter compounds, including comparable features in the mass spectra of 1,4-cyclohexadiene and 0-deuterated o-and p-cresols ; (ii) the mass spectra of the corresponding 0-deuterated benzyl and hydroxybenzyl alcohols ; (iii) meta-stable transitions.x-Complex structures may play an important role in the dissociation of some of the ions-for example, in the loss of D,O from molecular ions of m-and p-hydroxybenzyl alcohols.
Several I-rnethyloxindolidyl-3-niethines have been synthesized, either by condensation of l-methyloxindole with an aldehyde, or by a Wittig reaction of a chloromethylene compound with a I-methylisatin. Whenexamined in the mass spectrometer theexpected ion reactions were observed and, in addition, a reaction involving expulsion of the carbonyl group of the oxindole moiety and rearrangement of the residual fragment, to give a 1-methylbenzo[b]azepinium ion was observed. The anions of the oxindo-.lidyluracilmethines 4 and 5, (R = Me, R ' = OH) had an absorption band near 380 mb but the corresponding neutral molecules absorbed at 325-350 mp. The 5-nitrofuran derivatives 3 were the only compounds that inhibited the growth of Bacillrrs srrbtilis.
The previously reported reaction of dichloridodi(cyclopentadienyl)zirconium [(C5H5)2ZrCl2] with aniline or other bases has been shown to involve water as a reactant, with formation of the oxygen-bridged bis[chloridodi(cyclopentadienyl)- zirconium] oxide, [(C5H5),ZrCl]2O, containing the linkage Zr-0-Zr. The compound is diamagnetic, stable to air and water, and can be sublimed in a vacuum at 200-220�. The crystals are monoclinic, with four molecules per unit cell. The structure was established by mass, infrared, near infrared, and proton magnetic resonance spectral examination, and by reaction of the compound with deuterium-labelled and tritium-labelled hydrogen chloride to regenerate unlabelled dichloridodi(cyclopentadienyl)-zirconium.
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