(ETA-5-CYCLOPENTADIENYL)TRIALKYLPLATINUM PHOTOHYDROSILYLATION CATALYSTS - MECHANISM OF ACTIVE CATALYST FORMATION AND PREPARATION OF A NOVEL BIS(SILYL)PLATINUM HYDRIDE

被引:42
作者
BOARDMAN, LD
机构
[1] Industrial and Consumer Sector Research Laboratory, 3M Company, St. Paul
关键词
D O I
10.1021/om00060a042
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
The use of (eta5-cyclopentadienyl)trialkylplatinum complexes as photohydrosilylation catalysts is described. Photolysis of CpPtMe3 in the presence of a silane leads to the formation of an active hydrosilylation catalyst that evidence suggests is a heterogeneous platinum colloid. The catalyst is poisoned by elemental mercury but is not inhibited by dibenzo[a,e]cyclooctatetraene. In the presence of certain reactive silanes such as HMe2SiOSiMe3 the novel bis(silyl)platinum hydrides CpPt(SiR3)2H are formed as isolable species, which are not, however, intermediates on the primary pathway to the active hydrosilylation catalyst. The evidence suggests that the silyl methyl hydride complex CpPtMe(SiR3)H is the critical intermediate which is partitioned under the reaction conditions between colloidal platinum and CpPt(SiR3)2H. When they are treated with a second reactive silane, bis(silyl)platinum hydride complexes may undergo facile silane exchange via sequential reductive-elimination/oxidative-addition reactions at platinum to give other bis(silyl)platinum hydrides CpPt(SiR3')2H. A mechanism connecting CpPtMe3, CpPt(SiR3)2H, and colloidal platinum is proposed and discussed.
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页码:4194 / 4201
页数:8
相关论文
共 56 条
[1]   DIRECT OBSERVATION OF THE INTERMEDIATES IN THE PHOTOCHEMICAL-REACTION OF R3SICO(CO)4 WITH R'3SIH AND ESTABLISHMENT OF THE MECHANISM FOR R'3SICO(CO)4 FORMATION [J].
ANDERSON, FR ;
WRIGHTON, MS .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1984, 106 (04) :995-999
[2]   DIBENZO[A,E]CYCLOOCTATETRAENE IN A PROPOSED TEST FOR HETEROGENEITY IN CATALYSTS FORMED FROM SOLUBLE PLATINUM GROUP METAL-COMPLEXES [J].
ANTON, DR ;
CRABTREE, RH .
ORGANOMETALLICS, 1983, 2 (07) :855-859
[3]   SYNTHESIS OF BIS-MU-DIORGANOSILANEDIYL-AF-DIHYDRIDOBIS(TRIORGANOPHOSPHINE)DIPLATINUM COMPLEXES - CRYSTAL AND MOLECULAR-STRUCTURE OF [(PTH(MU-SIME2)[P(C6H11)3])2] [J].
AUBURN, M ;
CIRIANO, M ;
HOWARD, JAK ;
MURRAY, M ;
PUGH, NJ ;
SPENCER, JL ;
STONE, FGA ;
WOODWARD, P .
JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS, 1980, (04) :659-666
[4]   MECHANISTIC INVESTIGATION OF THE ZRME/PTME EXCHANGE IN CP-STAR-ZRME(MU-OCH2PH2P)2PTME2 [J].
BAXTER, SM ;
FERGUSON, GS ;
WOLCZANSKI, PT .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1988, 110 (13) :4231-4241
[5]   SMALL RING METALLACYCLES .6. METAL-CATALYZED REDISTRIBUTIONS OF ORGANOSILANES .5. PREPARATION OF CYCLOMETALLADISILOXANES OF THE TYPE M(SIMEROSIMER) (R = PHENYL AND BENZYL) AND THE CATALYZED REDISTRIBUTION OF (HRMESI)2O [J].
BELL, LG ;
GUSTAVSON, WA ;
THANEDAR, S ;
CURTIS, MD .
ORGANOMETALLICS, 1983, 2 (06) :740-745
[6]   PT-195 NMR-STUDY OF (ETA-5-CYCLOPENTADIENYL)TRIALKYLPLATINUM(IV) COMPLEXES [J].
BOARDMAN, LD ;
NEWMARK, RA .
MAGNETIC RESONANCE IN CHEMISTRY, 1992, 30 (06) :481-489
[7]  
BROWN HC, 1975, ORGANIC SYNTHESES VI
[8]   FORMATION OF SI-SI BONDS FROM SI-H BONDS IN THE PRESENCE OF HYDROSILATION CATALYSTS [J].
BROWNWENSLEY, KA .
ORGANOMETALLICS, 1987, 6 (07) :1590-1591
[9]   HOMOGENEOUS CATALYSIS .2. MECHANISM OF HYDROSILATION OF OLEFINS CATALYZED BY GROUP 8 METAL COMPLEXES [J].
CHALK, AJ ;
HARROD, JF .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1965, 87 (01) :16-&
[10]   ALKANE DEHYDROGENATION BY IRIDIUM COMPLEXES [J].
CRABTREE, RH ;
MELLEA, MF ;
MIHELCIC, JM ;
QUIRK, JM .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1982, 104 (01) :107-113