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Transformation of organic substrates on metal cluster complexes

1982; International Union of Pure and Applied Chemistry; Volume: 54; Issue: 1 Linguagem: Inglês

10.1351/pac198254010131

1365-3075

Herbert D. Kaesz, Carolyn B. Knobler, M. A. Andrews, Gregory Van Buskirk, Roman Szostak, Charles E. Strouse, Ying‐Chan Lin, A. Mayr,

Machine Learning in Materials Science

Synthesis and structure determination for the series of complexes (NCCH3 ) (CO) , (HN=CCH3 ) (CO) , HFe3(N=CHCH3)(CO)9 and H2Fe3(NCH2CH3)(CO)9 illustrate the stepwise reduction of acetonitrile on the face of a tn-iron complex.Attempts to extend this series to tn-ruthenium and tn-osmium complexes by reaction of the tnimetal dodecacarbonyls with aliphatic primary or secondary amines have instead led to the isolation ofp-(,) carboxamido complexes HM3 (O=CNRR' ) (CO) (M=Ru or Os; R=H, R' =CH3 or R=R'=CH3).These reactions are accompanied by loss of one mole of carbon monoxide at unprecedented low temperatures for such displacement.Reaction of Os3(CO)12 with a variety of nucleophiles (Nu=NR , CH or OR ) in polar media indicate that these attack at carbon of coordinated CO at temperatures below 0°C.The anionic complexes EOs3('-C(O)Nu)(CO)11]are formed showing characteristic -zI(CO) in the infrared in the region 1550 to 1630 cm' (depending on nucleophile and on the extent of ion pairing in the medium).These anions are seen next to lose one mole of carbon monoxide, less readily if ionpaired, to give anions containing a jJ-(Q,) bridging group.The latter anions can be protonated to neutral derivatives in overall high yields.A complex containing aJJ-(,N) bridging group, HO53(C(OH)=NCH3)(CO)10, is isolated as a minor product in the reaction of H2Os3(CO)10 with methylisocyanate.The isomer exists in equilibrium with a form, H0s3(C(O)- NHCH3)(CO)10, ngL/t=95/5 at 25°C in CDC13.The equilibrium mixture is observed slowly to isomenize to the fi-(Q,) bonded form with a half life of 17.5 d at 25°C (E = 92 kJ/mol in CDC13).These studies give new insights ainto elemental reaction steps that could participate in conversions by metal cluster complexes of CO and H2 (syngas) into oxygenated derivatives.