Chemistry of Reactive Organometallic Compounds at Low Temperatures and High Pressures: Reactions of M(CO)6 (M = Cr, Mo, W), (
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- 作者：Simon E. J. Goff ; Trevor F. Nolan ; Michael W. George ; and Martyn Poliakoff
- 刊名：Organometallics
- 出版年：1998
- 出版时间：June 22, 1998
- 年：1998
- 卷：17
- 期：13
- 页码：2730 - 2737
- 全文大小：145K
- 年卷期：v.17,no.13(June 22, 1998)
- ISSN：1520-6041
文摘
An unusual high-pressure (<5000 psi) and low-temperature (>30 K)cell is used to studythe photochemistry of d6 metal carbonyl complexes andrelated compounds in a polyethylene(PE) matrix. This approach combines some of the advantages oftraditional matrix isolationwith those of low temperature solvents (e.g. liquid Xe). UVphotolysis of M(CO)6 underpressures of N2 lead initially to the formation ofM(CO)5N2 and, on longer photolysis,tomore highly substitutedM(CO)6-n(N2)n(n 
f"> 4) species. Photolysis under a pressure ofH2leads to M(CO)5(
fchars/eta.gif" BORDER=0 >2-H2) andcis-M(CO)4(fchars/eta.gif" BORDER=0 >2-H2)2,disubstituted compounds which werepreviously unknown for Mo and W. The thermal reactivities of allof these compounds werequalitatively established by raising the temperature of the PE matrixand monitoring thereaction with CO. The UV photolysis of W(CO)5CS and(fchars/eta.gif" BORDER=0 >6-C6H3(CH3)3)M(CO)3(M = Crand Mo) also leads to previously uncharacterized H2 andN2 complexes. The low-temperature,high-pressure (LT-HP) cell allows gases to be exchanged during thecourse of a singleexperiment. The conditions needed for H2 andN2 to penetrate the PE and to be removedfrom it have been investigated, and this information has been used tostudy thermal exchangereactions between coordinated N2 andfchars/eta.gif" BORDER=0 >2-H2 ligands in M(CO)5Lcompounds. It was foundthat the reactivity followed the order Mo > Cr > W.
f"> 4) species. Photolysis under a pressure ofH2leads to M(CO)5(fchars/eta.gif" BORDER=0 >2-H2) andcis-M(CO)4(fchars/eta.gif" BORDER=0 >2-H2)2,disubstituted compounds which werepreviously unknown for Mo and W. The thermal reactivities of allof these compounds werequalitatively established by raising the temperature of the PE matrixand monitoring thereaction with CO. The UV photolysis of W(CO)5CS and(fchars/eta.gif" BORDER=0 >6-C6H3(CH3)3)M(CO)3(M = Crand Mo) also leads to previously uncharacterized H2 andN2 complexes. The low-temperature,high-pressure (LT-HP) cell allows gases to be exchanged during thecourse of a singleexperiment. The conditions needed for H2 andN2 to penetrate the PE and to be removedfrom it have been investigated, and this information has been used tostudy thermal exchangereactions between coordinated N2 andfchars/eta.gif" BORDER=0 >2-H2 ligands in M(CO)5Lcompounds. It was foundthat the reactivity followed the order Mo > Cr > W.