Ian R. Crossley

Methimazole-based ionic liquids.

The alkylation reaction of 2-mercapto-1-methylimidazole 1a with iodoethane and chlorobutane produced S-alkylmethimazole halides 2a and 2b which were subjected to anion metathesis with two different metal salts (MA) to afford methimazole-based room-temperature ionic liquids 3a, 3b, and 3c in 82%, 85%, and 87% yields, respectively. S-Alkylation giving 2a and 2b suggests that methimazole reacts through the thione tautomer.

The Organometallic Chemistry of Group 9 Poly(pyrazolyl)borate Complexes

Publisher Summary Poly (pyrazolyl)borate complexes of the group-10 triad are noticeably less numerous than many transition metals. However, the study of these materials has typically proven more systematic than for many others, dominated by investigation of reactivity traits with limited incidence of purely derivative examples. This chapter is concerned only with those materials that conform to the generally accepted definition of ‘‘organometallic,’’ and those that, while not strictly organometallic, are or have the potential to be of interest and utility to the organometallic chemist. Thus, the inclusion of all complexes featuring an M-C linkage– along with related metal hydrides, phosphanes, and nitrosyls– is implicit., Classical coordination compounds are included only where these possess substantiated or perceived utility to the field (e.g., synthetic precursors, catalysts) or serve to illustrate novel structural facets of far-reaching significance. Similar discretion is applied to the inclusion of more exotic materials that currently linger at the periphery of organometallic chemistry.

Facile self-assembly of the first diphosphametacyclophane

The reaction of isophthaloyl chloride and methyl-bis(trimethylsilyl)phosphane under mild conditions affords high yields of m-{-C(O)-C(6)H(4)(C(O)PMe)}(2) (1,10-dimethyl-1,10-diphospha-[3.3]-metacyclophane-2,9,11,18-tetraone): the first example of a diphosphametacyclophane.

Hydrofluorocarbon 245fa: a versatile new synthon in alkyne chemistry.

The CFC replacement 1,1,1,3,3-pentafluoropropane (HFC 245 fa) has been established as a convenient source of trifluoropropynyllithium under mild conditions; a range of novel and known trifluoropropynyl-containing systems has been prepared in a one-pot procedure.

The synthesis and chemistry of fluorovinyl-containing phosphines and the single crystal X-ray structure of SPPri2[(CF=CF2)

The first perfluorovinyl alkyl-containing phosphines of the type PR2(CFCF2) (R = Et, iPr, Cy) are reported. The reactivity of these air- and moisture-stable materials has been explored, both at the phosphorus centre and at the fluorovinyl moiety. When PR2(CXCF2) (X = F, Cl) is reacted with LiAlH4 a mixture of PR2(CXCFH) isomers and other defluorinated materials are produced, but the reaction with LiAlH(OBut)3 affords the single products Z-PR2(CFCFH) or E-PR2(CClCFH), respectively, in high yields. Reaction of the fluorovinyl alkyl phosphines with hydrogen peroxide, elemental sulfur or selenium yields fluorovinyl-containing phosphine oxides, sulfides and selenides, respectively. The phosphine sulfide SPPri2(CFCF2) is the first perfluorovinyl phosphorus(V) compound to be characterised crystallographically and it exhibits an unusually short [1.9358(9) A] PS bond. Reaction of fluorovinyl phosphines with XeF2 results in compounds of the type F2PR2(CFCF2), identified on the basis of multinuclear NMR studies. These compounds decompose in the presence of moisture to yield the respective phosphine oxides. Reaction of OPPh2(CFCF2) with Br2 results in bromine addition across the double bond to give OPPh2(CFBrCF2Br).

Tri­carbonyl(η6-chloro­benzene)­chromium

The title compound, [Cr(C(6)H(5)Cl)(CO)(3)], is the first group 6 tricarbonyl eta(6)-monohaloarene compound to be structurally characterized. It adopts a classic piano-stool structure, with the Cr(CO)(3) tripod assuming a syn-eclipsed conformation relative to the arene ring (varphi = 2.0 degrees ). The extended structure is dominated by intermolecular pi.H interactions (H.ring centroid = 2.94 A) and non-classical hydrogen bonds between carbonyl and arene moieties (O.H = 2.50-2.58 A).