TY - JOUR
T1 - "Bidentate" and "tridentate" sulfonamide ligands for titanium complexes
T2 - Crystal structures and solution dynamics elucidating an η2 or η3-coordination mode
AU - Hamura, Satoshi
AU - Oda, Takashi
AU - Shimizu, Yasuaki
AU - Matsubara, Kouki
AU - Nagashima, Hideo
PY - 2002
Y1 - 2002
N2 - Highly air- and moisture-sensitive complexes having sulfonamide ligands, (TsNR)2Ti(NMe2)2 (Ts = p-MeC6H4SO2), were prepared by treatment of two equivalents of TsNHR with Ti(NMe2)4 at room temperature. One of the compounds, where R = i-Pr (1), was studied in detail; the crystal structure of 1 revealed that both of the TsNi-Pr ligands were bound to the metal in an η2-coordination mode. Solution dynamics of 1 showed that an η1/η2 interconversion occurred above 60°C with an activation energy of 15.8 kcal mol-1. Treatment of Ti(NMe2)4 with the sulfonamide TsHN(CH2)2O(CH2)2NHTs (3), led to the formation of [TsN(CH2)2O(CH2)2NTs]Ti(NMe 2)2 (2) in high yield, in which the sulfonamide moiety was coordinated to the titanium center in an η3 (NON) mode. No sign of η1/η2 interconversion of the sulfonamide ligands was seen in solution. Treatment of 2 with Me3SiCl resulted in the formation of [{TsN(CH2)2O(CH2)2NTs}Ti(NMe 2)Cl]2 (4) and [{TsN(CH2)2O(CH2)2NTs}TiCl 2]2 (5). An X-ray structure determination of 4 revealed that sulfonyl oxygen bridging resulted in the formation of an eight membered ring.
AB - Highly air- and moisture-sensitive complexes having sulfonamide ligands, (TsNR)2Ti(NMe2)2 (Ts = p-MeC6H4SO2), were prepared by treatment of two equivalents of TsNHR with Ti(NMe2)4 at room temperature. One of the compounds, where R = i-Pr (1), was studied in detail; the crystal structure of 1 revealed that both of the TsNi-Pr ligands were bound to the metal in an η2-coordination mode. Solution dynamics of 1 showed that an η1/η2 interconversion occurred above 60°C with an activation energy of 15.8 kcal mol-1. Treatment of Ti(NMe2)4 with the sulfonamide TsHN(CH2)2O(CH2)2NHTs (3), led to the formation of [TsN(CH2)2O(CH2)2NTs]Ti(NMe 2)2 (2) in high yield, in which the sulfonamide moiety was coordinated to the titanium center in an η3 (NON) mode. No sign of η1/η2 interconversion of the sulfonamide ligands was seen in solution. Treatment of 2 with Me3SiCl resulted in the formation of [{TsN(CH2)2O(CH2)2NTs}Ti(NMe 2)Cl]2 (4) and [{TsN(CH2)2O(CH2)2NTs}TiCl 2]2 (5). An X-ray structure determination of 4 revealed that sulfonyl oxygen bridging resulted in the formation of an eight membered ring.
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U2 - 10.1039/b110481k
DO - 10.1039/b110481k
M3 - Article
AN - SCOPUS:0036010454
SN - 1470-479X
SP - 1521
EP - 1527
JO - Journal of the Chemical Society, Dalton Transactions
JF - Journal of the Chemical Society, Dalton Transactions
IS - 7
ER -