Triphenylene-Bridged Trinuclear Complexes of Cu: Models for Spin Interactions in Two-Dimensional Electrically Conductive Metal–Organic Frameworks

Reaction of 2,3,6,7,10,11-hexahydroxytriphenylene (HHTP) and 2,3,6,7,10,11-hexaaminotriphenylene (HATP) with [Cu(Me 3 tacn)] 2+ (Me 3 tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane) produces trigonal tricopper complexes [(Me 3 tacnCu) 3 (HOTP)] 3+ ( 1 ) and [(Me 3 tacnCu) 3 (HITP)] 4+ ( 2 ) (HOTP, HITP = hexaoxy- and hexaiminotriphenylene, respectively). These trinuclear complexes are molecular models for spin exchange interactions in the two-dimensional conductive metal–organic frameworks (MOFs) copper hexaoxytriphenylene (Cu 3 HOTP 2 ) and copper hexaiminotriphenylene (Cu 3 HITP 2 ). Whereas complex 1 is isolated with HOTP 3– bearing the same oxidation state as found in the oxy-bridged MOF, the triply oxidized HITP 3– found in Cu 3 HITP 2 is unstable with respect to disproportionation in the molecular model. Indeed, magnetic measurements reveal ligand-centered radical character for 1 and a closed-shell structure for 2, in agreement with the redox state of the ligands. All neighboring spins are antiferromagnetically coupled in 1 and 2 . These results help probe metal–ligand–metal interactions in conductive MOFs and provide potential inspiration for the synthesis of other two-dimensional materials with delocalized electrons.