
TY  - JOUR
A1  - Coates, JH 
A1  - Hadi, DA 
A1  - Lincoln, SF 
T1  - The preparation, characterization and solution chemistry of some nickel(II) and copper(II) complexes of 1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1982
VL  - 35
IS  - 5
SP  - 903
EP  - 909
KW  - 
UR  - https://doi.org/10.1071/CH9820903 
N2  - The preparation of the new ligand 1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane, (-N(Me)-(CH2)2-)4 (= L), and the complexes [NiL] (ClO4)2, [NiL(OCHNMe2)] (ClO4)2, [NiLN3] ClO4, [CuL] (ClO4)2, and [NiY] (ClO4)2, where Y = (-N(Me)(CH2)2N(Me)(CH2)3-)2, 1,4,8,11-tetra-methyl-1,4,8,11-tetraazacyclotetradecane, are described. The magnetic moments of the nickel((11) species are reported, and the labile low-spin/high spin equilibria characterizing the [NiLI2+ and [NiY]2+ systems over a range of temperatures and ionic strengths in aqueous solution are discussed. The spectrophotometric titration of the aqua ligands in [NiLH2O]2+, [CuLH2O]2+, and [NiYH2O]2+ against sodium hydroxide yields pKa values of 10.2 ± 0.2, 12.0 ± 0.3 and 10.7 ± 0.2, respectively, and a study, using Job's method of continuous variations, of the formation of azide species shows [NiLN3]+ and [NiYN3]+ to be formed predominantly in aqueous solution. 
ER  -

