A 30-Membered Nonanuclear Cobalt(II) Macrocycle Containing Phosphonate-Bridged Trinuclear Subunits

The reaction of Co­(ClO4)2·6H2O with (trichloromethyl)­phosphonic acid and 3,5-dimethyl-1H-pyrazole in a 3:1:6 ratio in the presence of triethylamine afforded [Co9(3,5-DMPz)12­(3,5-DMPzH)6­(Cl3CPO3)3]­(toluene)7 (1). The latter contains three trinuclear (Co3) subunits which are linked to each other by three bridging phosphonate ligands affording a 30-membered macrocycle. 1 contains an equilateral triangle comprising the phosphorus atoms of the bridging phosphonate groups. In solution, 1 breaks down into the trinuclear subunits as detected by electrospray ionization mass spectrometry.