Formation of Dinuclear Copper(II) Complexes from a Macrocycle with Built-in Pyrazole Groups.

The 22-membered macrocycle, containing four endocyclic pyrazole groups and two exocyclic pyridine groups, viz. (9,22-di(pyridin-2-ylmethyl)-1,4,9,14,17,22,27,28,29,30-decaaza-5,13,18,26-tetramethyl)pentacyclo[24.2.1.1(4,7).1(11,14).1(17,20)]triacontane-5,7(28),11(29),12,18,20(30),24(27),25-octaene (MePy22Pz), has been synthesized in an eleven-step procedure. Two dinuclear copper(II) compounds, viz. [Cu(2)(MePy22Pz)(NO(3))(4)](MeOH)(2) (A) and [Cu(2)(MePy22Pz)(CF(3)SO(3))(2)(H(2)O)(2)](CF(3)SO(3))(2)(MeOH)(2) (B), were prepared with this macrocycle. In both compounds the copper(II) ions are in a square pyramidal N(3)O(2) environment involving a pyrazole nitrogen, a pyridine nitrogen, and a tertiairy amine nitrogen and two oxygen atoms, which stem from two different nitrate anions in compound A and from a triflate anion and a water molecule in compound B. Two of the four pyrazole groups of the macrocycle do not participate in the coordination. The pendent pyridine groups protrude on opposite sides of the macrocycle. Consequently, the copper ions are on different sides of the macrocyclic ring and quite far apart with Cu-Cu distances of 8.668(4) Å in A and 6.814(1) Å in B.