TY - JOUR
T1 - Hydrolysis and condensation processes of titanium iso-propoxide modified with catechol
T2 - An NMR study
AU - Egawa, Kentaro
AU - Suzaki, Kentaro
AU - Sugahara, Yoshiyuki
N1 - Funding Information:
The authors gratefully thank Prof. Kazuyuki Kuroda, Department of Applied Chemistry at Waseda University, for his valuable suggestions. This work was financially supported in part by the Grant-in-Aid for Scientific Research (No. 14655250) from the Ministry of Education, Science, Sports, and Culture, Japan and by 21COE “Practical Nano-Chemistry” from MEXT, Japan.
PY - 2004/5
Y1 - 2004/5
N2 - The hydrolysis and condensation processes of titanium iso-propoxide modified with catechol (C6H4(OH)2; H 2cat) have been investigated by 1H, 13C and 17O nuclear magnetic resonance spectroscopy. The hydrolysis reactions of the modified titanium isoo-propoxide in the system with Ti:tetrahydrofuran (THF):H2O = 1:20:x (x =1,2 and 5 in a molar ratio) are essentially completed in the initial stage (<1 h), and the condensation reactions also proceed significantly during this stage. Upon hydrolysis with H2O/Ti = 1, the iso-propoxy groups are selectively hydrolyzed and the catecholate groups remain bound to titanium. With H2O/Ti = 2 and 5, both the iso-propoxy and catecholate groups are hydrolyzed, and the hydrolysis of the iso-propoxy groups is relatively preferential. Approximately half the catecholate groups are stably bound to titanium, even after hydrolysis with H2O/Ti = 5.
AB - The hydrolysis and condensation processes of titanium iso-propoxide modified with catechol (C6H4(OH)2; H 2cat) have been investigated by 1H, 13C and 17O nuclear magnetic resonance spectroscopy. The hydrolysis reactions of the modified titanium isoo-propoxide in the system with Ti:tetrahydrofuran (THF):H2O = 1:20:x (x =1,2 and 5 in a molar ratio) are essentially completed in the initial stage (<1 h), and the condensation reactions also proceed significantly during this stage. Upon hydrolysis with H2O/Ti = 1, the iso-propoxy groups are selectively hydrolyzed and the catecholate groups remain bound to titanium. With H2O/Ti = 2 and 5, both the iso-propoxy and catecholate groups are hydrolyzed, and the hydrolysis of the iso-propoxy groups is relatively preferential. Approximately half the catecholate groups are stably bound to titanium, even after hydrolysis with H2O/Ti = 5.
KW - Catechol, hydrolysis
KW - Chemical modification
KW - Condensation
KW - Nuclear magnetic resonance
KW - Sol-gel process
KW - Titanium iso-propoxide
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U2 - 10.1023/B:JSST.0000034695.21475.76
DO - 10.1023/B:JSST.0000034695.21475.76
M3 - Article
AN - SCOPUS:3142764918
VL - 30
SP - 83
EP - 88
JO - Journal of Sol-Gel Science and Technology
JF - Journal of Sol-Gel Science and Technology
SN - 0928-0707
IS - 2
ER -