Transition metals such as Fe in porphyrin complexes are known to bind or react with O2,and such reactions are critical to many biological functions and catalytic oxidation using O2.The transition metals in these react...Transition metals such as Fe in porphyrin complexes are known to bind or react with O2,and such reactions are critical to many biological functions and catalytic oxidation using O2.The transition metals in these reactions often contain valence d electrons,and oxidation of metals is an important step.In recent years,reactions of O2 with d0 transition metal complexes such as Hf(NR2)4(R=alkyl) have been used to make metal oxide thin films as insulating gate materials in new microelectronic devices.This feature article discusses our recent studies of such reactions and the formation of TiO2 thin films.In contrast to the reactions of many dn complexes where metals are often oxidized,reactions of d0 complexes such as Hf(NMe2)4 and Ta(NMe2)4(SiR3) with O2 usually lead to the oxidation of ligands,forming,e.g.,-ONMe2 and -OSiR3 from-NMe2 and-SiR3 ligands,respectively.Mechanistic and theoretical studies of these reactions have revealed pathways in the formation of the metal oxide thin films as microelectronic materials.展开更多
Treatment of RuCl2(PPh3)3 with 6-dimethylaminopentafulvene in THF in the presence of water produced(η5-C5H4CHO) RuCl(PPh3)2, which was reduced by NaBH4 to give the Ru–H···HO dihydrogen bonded complex(...Treatment of RuCl2(PPh3)3 with 6-dimethylaminopentafulvene in THF in the presence of water produced(η5-C5H4CHO) RuCl(PPh3)2, which was reduced by NaBH4 to give the Ru–H···HO dihydrogen bonded complex(η5-C5H4CH2OH) RuH(PPh3)2. The dihydrogen bonded complex(η5-C5H4CH2OH)RuH(PPh3)2 could also be synthesized by the reduction of complex(η5-C5H4CHO)RuH(PPh3)2, which was obtained by the reaction of RuHCl(PPh3)3 with 6-dimethylaminopentafulvene in the presence of water. The analogous dihydrogen bonded osmium complex(η5-C5H4CH2OH)OsH(PPh3)2 was similarly prepared. Single crystal structures and DFT calculations support the presence of intra-molecular H···H interaction, with separations of around 1.9 to 2.0 .展开更多
基金Supported by the U.S. National Science Foundation (CHE-051692), Research Grants Council of Hong Kong and the British Royal Society Kan Tong Po Visiting Professorship Program
文摘Transition metals such as Fe in porphyrin complexes are known to bind or react with O2,and such reactions are critical to many biological functions and catalytic oxidation using O2.The transition metals in these reactions often contain valence d electrons,and oxidation of metals is an important step.In recent years,reactions of O2 with d0 transition metal complexes such as Hf(NR2)4(R=alkyl) have been used to make metal oxide thin films as insulating gate materials in new microelectronic devices.This feature article discusses our recent studies of such reactions and the formation of TiO2 thin films.In contrast to the reactions of many dn complexes where metals are often oxidized,reactions of d0 complexes such as Hf(NMe2)4 and Ta(NMe2)4(SiR3) with O2 usually lead to the oxidation of ligands,forming,e.g.,-ONMe2 and -OSiR3 from-NMe2 and-SiR3 ligands,respectively.Mechanistic and theoretical studies of these reactions have revealed pathways in the formation of the metal oxide thin films as microelectronic materials.
基金supported by the Hong Kong Research Grant Council(HKUST 602611,HKUST-601812,CUHK7/CRF/12G-2)
文摘Treatment of RuCl2(PPh3)3 with 6-dimethylaminopentafulvene in THF in the presence of water produced(η5-C5H4CHO) RuCl(PPh3)2, which was reduced by NaBH4 to give the Ru–H···HO dihydrogen bonded complex(η5-C5H4CH2OH) RuH(PPh3)2. The dihydrogen bonded complex(η5-C5H4CH2OH)RuH(PPh3)2 could also be synthesized by the reduction of complex(η5-C5H4CHO)RuH(PPh3)2, which was obtained by the reaction of RuHCl(PPh3)3 with 6-dimethylaminopentafulvene in the presence of water. The analogous dihydrogen bonded osmium complex(η5-C5H4CH2OH)OsH(PPh3)2 was similarly prepared. Single crystal structures and DFT calculations support the presence of intra-molecular H···H interaction, with separations of around 1.9 to 2.0 .
