865292-86-0Relevant articles and documents
Some organometallic chemistry of molybdenum complexes that contain the [HIPTN3N]3- triamidoamine ligand, {[3,5-(2,4,6.i.Pr 3C6H2)2C6H 3NCH2CH2]3N}3-
Byrnes, Matthew J.,Dai, Xuliang,Schrock, Richard R.,Hock, Adam S.,Mueller, Peter
, p. 4437 - 4450 (2005)
Reactions between [HIPTN3N]Mo(N2) and ethylene, acetylene, or CO yield Mo(η2-C2H4), Mo(η2-C2H2), and Mo(CO), respectively ([HIPTN3N]3- = [3,5-(2,4,6-i-Pr3C 6H2)2C6H3NCH 2- CH2]3N3-; HIPT = hexaisopropylterphenyl; [HIPTN3N]Mo = Mo). All are paramagnetic C3 symmetric species. Attempts to prepare Mo(CO) through reduction of MoCl with Na/Hg in THF under carbon monoxide yielded [Mo(CO)]Na, in which the sodium ion is believed to be bound within the HIPT aryl system. Addition of a variety of acids such as [Et3NH]BAr′4 to [Mo(CO)]Na led to formation of the carbonyl hydride, Mo(CO)H, which also could be prepared by treating MoH with CO. Reactions between MoH and ethylene, 1-hexene, or 1-octene in benzene yield paramagnetic, red Mo(CH2R) complexes (CH2R = ethyl, hexyl, or octyl). MoMe could be prepared by treating MoCl with AlMe3 at room temperature over a period of 2 days. Treatment of MoH with acetylene affords yellow diamagnetic Mo(η2- CHCH2) plus polyacetylene. The MoCH2R complexes decompose at ～150 °C to yield the alkylidyne complexes, Mo=CR, quantitatively. No change was observed upon heating a toluene solution of MoCH3 to 160 °C for 24 h. However, Mo=CH could be prepared from a mixture of MoCl, 3 equiv of dichloromethane, and a large excess of magnesium powder in THF under argon at 90 °C. Although we have seen no evidence of thermal rearrangement of Mo(η2-CHCH2) to Mo=CCH3, that rearrangement is readily catalyzed by [2,6-LutH]BAr′4. Attempts to prepare Mo-C=CH from [Mo(NH3)]BAr′ 4 and NaC=CH led to formation of a yellow crystalline compound that was shown in an X-ray study to be one in which the acetylide had inserted into an ortho C-H bond in the phenyl ring attached to the amido nitrogen. Orange paramagnetic MoCN can be isolated in good yield from the reaction between [Mo(NH3)]BPh4 and [Bu4N]CN in fluorobenzene. Electrochemical studies in 0.1 M [Bu 4N]BAr′ 4 in PhF at room temperature revealed reversible couples for Mo(C2H4)+/0 and Mo(C2H2)+/0 at -0.42 and -0.94 V, respectively, while Mo(CN) exhibits two redox processes at -0.27 and -1.61 V that we assign to the Mo(CN)+/0 and Mo(CN)0/- redox couples, respectively. Addition of [Cp2Fe]BAr′ 4 to a solution of Mo(η2-C2H2) in C 6D6 produces diamagnetic [Mo(η2-C 2H2)]BAr′ 4, while addition of [Cp 2Fe]BAr'4 to a C6D6 solution of Mo(η2C2H4) led to formation of diamagnetic [Mo(C2H4)]BAr′ 4. Structures of Mo(C 2H4), [Mo(C2H4)]BAr′ 4, Mo(CH2CH3), and Mo(C=CH) were determined through X-ray studies.
