Showing papers by "John F. Nixon published in 1996"
122 citations
TL;DR: In this article, a 2-arsa-1,3-dionatolithium(I) complexes with R = But, L = ½ dme or Et2O and the antimony compound showed them to be dimeric in the solid state with respect to the metal and anionic ligands, the dimeric units being linked in an infinite polymeric chain by bridging dme molecules or solvated with Et 2O.
Abstract: Reactions of [Li{E(SiMe3)2}(dme)](E = As or Sb, dme = MeOCH2CH2OMe), with a range of acid chlorides, RCOCl, afforded the novel 2-arsa-1,3-dionatolithium(I) complexes [[graphic omitted]}L](R = But, L =½ dme or Et2O; R = C6H2Pri3-2,4,6, L = Et2O; R = C6H2But3-2,4,6, L = dme), and the first example of a 2-stiba-1,3-dionatolithium(I) complex [{[graphic omitted]}(dme)05]2}∞] X-Ray crystal structural analyses for the complexes with R = But, L =½ dme or Et2O and the antimony compound show them to be dimeric in the solid state with respect to the metal and anionic ligands, the dimeric units being linked in an infinite polymeric chain by bridging dme molecules or solvated with Et2O A dimeric structure can also be inferred when R = C6H2Pri3-2,4,6, L = Et2O In solution these four compounds display fluxional behaviour Treatment with HCl of the monomeric compound having R = C6H2But3-2,4,6, L = dme yields the known diacylarsane [As{C(C6H2But3-2,4,6)O}{C(C6H2But3-2,4,6)OH}] the crystal structure of which reveals the enol form with the alcoholic proton intramolecularly hydrogen bonded to the opposing oxygen centre of the ligand
15 citations
TL;DR: The first known ruthenium(0) complex of a 1,2,4-triphosphole was reported in this article, which undergoes a novel hydrogen migration reaction from the η4-cycloocta-1,5-diene coligand on heating.
14 citations
TL;DR: In this paper, the synthesis and structural determinations of novel complexes of the type [Ir4(CO)11L]{L = [Fe(η5-P3C2But2)(η 5-P2C3But3)] or [Fe[Fe[5-C5H5]-P3CH2(CMe2)CBut] involving an unusual C-H activation are described.
12 citations
TL;DR: In this article, the solid state structure of 2b, established by an X-ray analysis, is that of the Td-like isomer, although the low-temperature 31P-1H NMR spectrum showed the presence of both C3v- and Tdlike isomers in solution.
Abstract: The reactions of NBu4[Ir4(CO)11Br]1 with equivalent amounts of [Fe(η5-P3C2But2)(η5-P2C3But3)] L1 or [Fe(η5-C5H5)(η5-P3C2But2)] L2 in the presence of AgSbF6 gave good yields of [Ir4(CO)11(η1-L)]2a or 2b, besides [Ir4(CO)10(η1-L)2]3a and 3b, respectively, in which the ligands are bound via the PA atom. The solid-state structure of 2b, established by an X-ray analysis, is that of the Td-like isomer, although the low-temperature 31P-{1H} NMR spectrum showed the presence of both C3v- and Td-like isomers in solution. Compound 2a underwent facile conversion to [Ir4(CO)10(µ-η2-L1)]4avia CO loss and further interaction of the adjacent PB atom of L1. Compound 2b reacted with 1 in the presence of AgSbF6 to yield [Ir4(CO)11(µ-η1 : η1-L2)Ir4(CO)11]5b, in which the second Ir4 cluster was ligated via PC, rather than PB, according to NMR spectroscopy. This compound underwent clean conversion into [Ir4H(CO)10{Fe(η5-C5H5)[η5-P3C(CMe2CH2)CBut]}Ir4(CO)11]6b,via CO loss and oxidative addition of a C–H bond of a tert-butyl substituent in the P3C2But2 ring. The molecular structure of 6b was determined by a single crystal X-ray diffraction analysis, which showed that C–H activation occurred on the Ir4 cluster bound via PC.
9 citations
TL;DR: In this paper, the µ4-phosphinidene cluster compounds [Ru4{µ4-PC(CO)But}2(µ-CO)(CO)10] and [FeRu3-µ3-PC-CO(CO)-But} 2( µ -CO)9] were prepared by addition of the isolobal 12-valence electron fragments Ru( CO)2 and Fe( CO 2 to the nido-cluster.
7 citations
TL;DR: The first examples of platinum(II) complexes of the P4C4Bu4 t and P5C5Bu5 t were described and detailed nmr and X-ray crystallographic structural studies have been carried out on the complexes as mentioned in this paper.
Abstract: The first examples of platinum(II) complexes of the P4C4Bu4 t and P5C5Bu5 t “cages” are described and detailed nmr and X-ray crystallographic structural studies have been carried out on the complexes trans-[PtCl2(PR3)(P4C4Bu4 t)], trans-[(PtCl2(PR3)]2(P4C4Bu4 t)], (R = Et, Bu), and trans-[PtCl2(PEt3)-(P5C5Bu5 t)].
5 citations
TL;DR: In this article, a crystal structure analysis revealed a nido structure for both complexes in agreement with a contribution of four electrons to the cluster framework by each phosphinidene ligand.
Abstract: Reaction of 1Bu[sbnd]C[tbnd]P with [Ru3(CO)12] or [Os3(CO)12] afforded the novel phosphinidene complexes [Ru3(CO)9(PC(CO)1Bu}2] 1 or [Os1(CO)9(PC(CO)1Bu}2] 2, respectively. A crystal structure analysis revealed a nido structure for both complexes in agreement with a contribution of four electrons to the cluster framework by each phosphinidene ligand. A minor product of the reaction with [Os3(CO)12] is the complex [Os3(CO)9(P(C(CO)1Bu)C(1Bu)P(Os3(CO)11))] 3, consisting of two triosmium units linked by a P[sbnd]C[sbnd]P framework resulting from coupling of phosphinidene and phospha-alkyne fragments. Complex 3 was also characterized by means of a crystal structure analysis.
3 citations
TL;DR: Recent developments in synthetic, structural and spectroscopic aspects of organometallic compounds derived from phospha-alkynes are reviewed in this article, where the authors present a review of the main aspects of these compounds.
Abstract: Recent developments in synthetic, structural and spectroscopic aspects Of novel organometallic compounds derived from phospha-alkynes are reviewed.
1 citations
TL;DR: The activation barrier for the [1, 3]-phosphorus migration in the title compound is estimated (MP4SDTQ/6-31 G*/6−31 G+ ZPE) to be 11.62 kcal mol-1(1 cal = 4.184 J), which is considerably smaller than the barrier (31.13 kcal mol−1) for [1-3]-carbon migration in a corresponding hydrocarbon.
Abstract: The activation barrier for the [1, 3]-phosphorus migration in the title compound is estimated (MP4SDTQ/6–31 G*//MP2/6–31 G*+ ZPE) to be 11.62 kcal mol–1(1 cal = 4.184 J), which is considerably smaller than the barrier (31.13 kcal mol–1) for [1,3]-carbon migration in the corresponding hydrocarbon.