COORDINATION CHEMISTRY OF 1,4,7-TRIAZACYCLONONANE (L) AND ITS N-METHYLATED DERIVATIVE (L') WITH SILVER(I) AND MERCURY(II) - THE CRYSTAL-STRUCTURES OF [AGL'2]PF6 AND [AGL'(SCN)]

Reaction of AgPF6 in acetonitrile with an equimolar amount of the macrocycle 1,4,7-triazacyclononane (L) and addition of [NBu4]X (X = Cl, Br, I or CN) affords colourless to yellow precipitates of [AgL(X)]. The complexes [AgL'(X)] (X = SCN or CN) (L' = 1,4,7-trimethyl-1,4,7-triazacyclononane) have been prepared similarly. When the ligand to AgPF6 ratio was 2:1 in ethanolic solution, colourless crystals of [AgL2]PF6 and [AgL'2]PF6 were obtained, respectively. A binuclear species [LAg(mu-CN)AgL]PF6 has been obtained from a solution of AgPF6 and L (1:1) in pyridine upon addition of NaCN (0.5 equivalent). Mercury(II) chloride reacts in water with L (1:2) and addition of NaPF6 to yield [HgL2][PF6]2; with L' the complex [HgL'(Cl)]PF6 was obtained. Crystals of [AgL'2]PF6 are tetragonal, space group P4(2)/m (no. 84), with a = 10.134(1), c = 12.771(2) angstrom, and Z = 2. Crystals of [AgL'(SCN)] are orthorhombic, space group Pcmn (no. 62), with a = 9.497(5), b = 11.837(8), c = 26.00(1) angstrom and Z = 8.