TY - JOUR
T1 - Pincer "hemilabile" effect. PCN platinum(II) complexes with different amine "arm length"
AU - Poverenov, Elena
AU - Gandelman, Mark
AU - Shimon, Linda J.W.
AU - Rozenberg, Haim
AU - Ben-David, Yehoshoa
AU - Milstein, David
PY - 2005/3/14
Y1 - 2005/3/14
N2 - The reactivity of the "long arm" PCN-type pincer ligand C 6H4[CH2P(tBu)2](CH2) 2N(CH3)2 (1), which forms complexes bearing a six-member ed amine chelate and a five-membered phosphine chelate, was compared with that of the new "normal" PCN ligand C6H 4[CH2P-(tBu)2](CH2)N(CH 2CH3)2 (2), which leads to formation of complexes bearing two five-membered chelates. The chloride complexes (PCN)PtCl (3, 4) and the unsaturated cationic complexes [(PCN)Pt]+X- (X = BF4, OTf) (5,6,7), based on both PCN ligands, were prepared and reacted with different reagents to give aqua, [(PCN-1)Pt(H2O)] +BF4- (10); hydroxo, (PCN-1)Pt(OH) (11); carbonyl [(PCN)Pt(CO)]+BF4- (8, 9); and hydride, (PCN-1)PtH (16) complexes. The structures of complexes 4, 6, 8, 10, 11, and 12 were determined by X-ray crystallography. When both carbonyl complexes were treated with hydrogen gas, the "long arm" PCN-1-based complex 8 led to formation of a trimeric cluster, [C6H6[CH 2P(tBu)2]-(CH2)2N(CH 3)2Pt(CO)]3 (12), while the "normal" PCN-based complex 9 remained unchanged under the same conditions. This observation clearly demonstrates the very significant effect of the amine arm length (five- vs six-membered chelate) on the hemilability of the ligand and the reactivity of the corresponding complexes.
AB - The reactivity of the "long arm" PCN-type pincer ligand C 6H4[CH2P(tBu)2](CH2) 2N(CH3)2 (1), which forms complexes bearing a six-member ed amine chelate and a five-membered phosphine chelate, was compared with that of the new "normal" PCN ligand C6H 4[CH2P-(tBu)2](CH2)N(CH 2CH3)2 (2), which leads to formation of complexes bearing two five-membered chelates. The chloride complexes (PCN)PtCl (3, 4) and the unsaturated cationic complexes [(PCN)Pt]+X- (X = BF4, OTf) (5,6,7), based on both PCN ligands, were prepared and reacted with different reagents to give aqua, [(PCN-1)Pt(H2O)] +BF4- (10); hydroxo, (PCN-1)Pt(OH) (11); carbonyl [(PCN)Pt(CO)]+BF4- (8, 9); and hydride, (PCN-1)PtH (16) complexes. The structures of complexes 4, 6, 8, 10, 11, and 12 were determined by X-ray crystallography. When both carbonyl complexes were treated with hydrogen gas, the "long arm" PCN-1-based complex 8 led to formation of a trimeric cluster, [C6H6[CH 2P(tBu)2]-(CH2)2N(CH 3)2Pt(CO)]3 (12), while the "normal" PCN-based complex 9 remained unchanged under the same conditions. This observation clearly demonstrates the very significant effect of the amine arm length (five- vs six-membered chelate) on the hemilability of the ligand and the reactivity of the corresponding complexes.
UR - http://www.scopus.com/inward/record.url?scp=15944383405&partnerID=8YFLogxK
U2 - 10.1021/om049182m
DO - 10.1021/om049182m
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AN - SCOPUS:15944383405
SN - 0276-7333
VL - 24
SP - 1082
EP - 1090
JO - Organometallics
JF - Organometallics
IS - 6
ER -