Compounds of Copper(II) and Nickel(II) with 6,8,8,13,13,15-Hexamethyl-1,2,4,5,9,12- hexaazacyclopentadeca-5,15(1)-diene and Some 3-Substituted Homologues

Abstract

Copper(II) and nickel(II) compounds, [M(L)]²⁺, of the macrocyclic ligand 6,8,8,13,13,15-hexamethyl-1,2,4,5,9,12-hexaazacyclopentadeca-5,15(1)-diene are formed by reaction of compounds of 4,4,9,9-tetramethyl-5,8-diazadodecane-2,11-dione dihydrazone with methanal. Analogous reactions with aldehydes RHCO, or ketones RR′CO, form compounds of 3-R or 3-RR′ substituted ligands, [M(r- L)]²⁺ or [M(rr′-L)]²⁺, respectively. The nickel(II) cations form singlet ground state salts, e.g. [Ni(L)]X₂, X = [ClO₄]^- or ½[ZnCl₄]^2-, and also triplet ground state compounds, e.g. [Ni(L) (NCS)₂] and [Ni(L)(X)] (ClO₄) (X = NO₂^-, C₂O₄^2-, N₃^-, etc.). The structures of [Cu(L)] (ClO₄)₂, [Ni(L)] (ClO₄)₂, the 3-propyl compound formed from butanal, [Cu(pr-L)] (ClO₄)₂.H₂O, and the compounds of 9,11,11,16,16,18-hexamethyl-7,8,12,15,19,20-hexaazaspiro[5.14]eicosa-8,18(1)-diene (chex-L), formed from cyclohexanone, namely [Cu(chex-L)] (ClO₄)₂.MeOH, [Ni(chex-L)] (ClO₄)₂, and [Ni(chex-L)] (ClO₄)₂.MeOH, were determined. All have the metal ions in tetrahedrally twisted square-planar coordination, by N¹, N⁵, N⁹ and N¹² , with N⁹N¹²-rac, for the (L) and (pr-L) compounds, or by the structurally equivalent N³, N⁷, N¹⁰ and N¹⁴, with N⁷N¹⁰-rac, for the (chex-L) compounds. The [Cu(L)]²⁺ and [Cu(pr-L)]²⁺cations have saddle-like macrocycle conformations, with approximate mirror symmetry, while the other compounds have ′twisted′ macrocycle conformations with approximate twofold symmetry {[Cu(L)] (ClO₄)₂, C₁₅H₃₂Cl₂CuN₆O₈, orthorhombic,P 2₁2₁2₁, a 8·562(7), b 13·096(8), c 20·257(6) Å, Z 4, R 0·041 for 1540 reflections; [Ni(L)] (ClO₄)₂, C₁₅H₃₂Cl₂N₆NiO₈, orthorhombic, P2₁/n, a 13·500(3), b 9·207(2), c 19·478(5) Å, β 103·94(2)°, Z 4, R₁ 0·055 for 2650 reflections; [Cu(Pr-L)] (ClO₄)₂.H₂O, C₁₈H₄₀Cl₂CuN₆O₉, monoclinic, C 2, a 24·229(5), b 13·780(3), c 8·877(2) Å, β 108·79(3)°, Z 4, R₁ 0·067 for 1765 reflections; [Cu(chex-L)] (ClO₄)₂.MeOH, C₂₁H₄₄Cl₂CuN₆O₉, monoclinic, C 2/c, a 17·086(5), b 24·539(2), c 14·496(1) Å, β 89·94(2), Z 8, R₁ 0·072 for 2521 reflections; [Ni(chex-L)] (ClO₄)₂, C₂₀H₄₀Cl₂N₆NiO₈, monoclinic, P 2₁/c, a 14·820(2), b 18·599(4), c 10·282(1) Å, β 106·26(1)°, Z 4, R₁ 0·067 for 2552 reflections; [Ni(chex-L)] (ClO₄)₂.MeOH, C₂₁H₄₄Cl₂CuN₆O₉, monoclinic, C 2/c, a 14·451(2), b 24·11(2), c 16·740(3) Å, β 90·14(1)°, Z 8, R₁ 0·064 for 2598 reflections}.