Transition-element complexes with aliphatic Schiff bases. Part IX. Heterocyclic complexes of nickel(II) formed by reaction of mixtures of diaminoethane and 1,2- or 1,3-diaminopropanenickel complexes with acetone

(3,5,7,7,12,14,14-Heptamethyl-1,4,8,11-tetraazacyclotetradec-4-11-diene)nickel(II) revisited and some (2,5,5,7,12,12,14-heptamethyl-1,4,8,11-tetraazacyclotetradecane)nickel(II) compounds

“…These studies confirm that the reported reaction of equimolar mixtures of tris(ethane-1,2-diamine) and tris(rac-propane-1,2-diamine)nickel(II) perchlorates with acetone [6] does form (3,5,7,7,12,14,14-heptamethyl-1,4-8,11-tetraazacyclotetradec-4,11-diene)nickel(II) perchlorate, [Ni(trans-Me 7 [14]diene)](ClO 4 ) 2 . However the reaction also forms (5,7,7,12,14,14-hexamethyl-1,4-8,11-tetraazacyclotetradec-4,11-diene)nickel(II), and a perchlorate salt with equimolar proportions of these cations initially crystallises.…”

“…1. 6 The chemistry of the hexa-and octamethyl macrocyclic compounds has been extensively studied, 1,5 but that of this heptamethyl homologue has received no attention for over 40 years, and even the formation of this cation has not been confirmed. This issue is now addressed.…”

“…The Me 6 [14]diene and meso-Me 8 [14]diene macrocycles are also formed as the salts [H 2 (Me 6 [14]diene)](ClO 4 ) 2 or [H 2 (meso-Me 8 [14]diene)](ClO 4 ) 2 by reaction of mono-protonated salts of ethane-1,2-diamine or rac-propane-1,2-diamine with acetone. 1,4,5,[7][8][9][10] The possibility that reaction of a mixture of these salts with acetone could form the heptamethyl homologue has been investigated.…”

“…Reaction of tris(ethane-1,2-diamine)nickel(II) perchlorate with acetone, over a period of days at ambient temperatures, forms a mixture of 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradec-4,11-diene)nickel(II) perchlorate, [Ni(transMe 6 [14]diene)](ClO 4 ) 2 (which can occur as interconvertable N-meso-and N-racisomers) and [5,7,7,12,12,14-(hexamethyl-1,4,8,11-tetraazacyclotetradec-4,14(1)-diene)nickel(II)] perchlorate, [Ni(cis-Me 6 [14]diene)](ClO 4 ) 2 , see Fig. 1.…”

“…The structure of [Ni(meso-III-Me6 [14]ane)][ZnCl 4 ] was determined as structures 7 (at 120 K) and 8 (at 280 K) for comparison. Structures 4, 5, 7 and 8 are isomorphous.The asymmetric unit for structures 4 -6 includes a square-planar [Ni(macH)] 2+ cation without inherent symmetry, with obvious methyl substituents at ring positions 5, 5, 7, 12, 12 and 14 of the 1,4,8,11-tetraazacyclotetradecane ligand.…”