131680-90-5Relevant academic research and scientific papers
Polyazamacrocycles. Part 7. Kinetics of Aquation of trans-Dichloro and trans-Chloro (Nitro) Complexes of Cobalt(III) with Tetra-aza Macrocycles
Bembi, Ramesh,Roy, Tapashi G.,Jhanji, Amrit K.,Maheswari, Alka
, p. 3531 - 3534 (1990)
Kinetic studies on the aquation of trans-+ and trans-+ (L = tetra-aza macromolecule) complexes show large variation in rates.The dependence of aquation rates on conformational strain energy is true only for a limited number of compounds.The rate enhancements can be rationalised in terms of the ability of the macromolecule to fold across a fold axis.The large-ringed macrocyclic complexes trans-6Cl2>+ (L6 = 1,4,8,11-tetra-azacyclohexadecane) and trans-7Cl2>+ (L7 = 1,4,8,11-tetra-azacycloheptadecane) aquate at much lower rates due to curtailed folding ability.The N...N bite distance also suggest a lower aquation rate for these complexes.The complexes 2,5,5,7,9,12,12,14-octamethyl- and 5,7,12,14-tetraethyl-5,12-dimethyl-1,4,8,11-tetra-azacyclotetradecane aquate with low rates lying in a narrow range.No specific trends can be identified in these complexes.These studies also show that very large aquation rate enhancements in cobalt(III) complexes of 14-membered macrocycles are possible only if gem-dialkyl groups are present.
