Isomeric 4,2′:6′,4″- and 3,2′:6′,3″-Terpyridines with Isomeric 4′-Trifluoromethylphenyl Substituents: Effects on the Assembly of Coordination Polymers with [Cu(hfacac)2] (Hhfacac = Hexafluoropentane-2,4-dione)

The isomers 4′-(4-(trifluoromethyl)phenyl)-4,2′:6′,4″-terpyridine (1), 4′-(3-(trifluoromethyl)phenyl)-4,2′:6′,4″-terpyridine (2), 4′-(4-(trifluoromethyl)phenyl)-3,2′:6′,3″-terpyridine (3), and 4′-(3-(trifluoromethyl)phenyl)-3,2′:6′,3″-terpyridine (4) have been prepared characterized. single crystal structures of 1 2 were determined. 1D-polymers [Cu2(hfacac)4(1)2]n·2nC6H4Cl2 (Hhfacac = 1,1,1,5,5,5-hexafluoropentane-2,4-dione), [Cu(hfacac)2(2)]n·2nC6H5Me, [Cu2(hfacac)4(3)2]n·nC6H4Cl2, [Cu2(hfacac)4(3)2]n·nC6H5Cl, [Cu(hfacac)2(4)]n·nC6H5Cl formed by reactions 1, 2, 3 4 with [Cu(hfacac)2]·H2O under conditions growth layering four these coordination polymers on a preparative scale. [Cu(hfacac)2(2)]n·2nC6H5Me are zig-zag chains the different substitution position CF3 group in does not affect this motif. Packing polymer is governed mainly C–F...F–C contacts, there no inter-polymer π-stacking interactions. conformation 3,2′:6′,3″-tpy unit [Cu2(hfacac)4(3)2]n·nC6H4Cl2 differs, leading to structural motifs 1D-polymer backbones. In [Cu(hfacac)2(4)]n·nC6H5Cl, peripheral 3-CF3C6H4 accommodated pocket between two {Cu(hfacac)2} units engages C–Hphenyl...F–Chfacac contacts which lock phenylpyridine near planar conformation. interactions 4′-trifluoromethylphenyl-3,2′:6′,3″-tpy domains key packing interactions, contrasts incorporating 2. We use powder X-ray diffraction demonstrate that assemblies reproducible, switch from 4,2′:6′,4″- metal-binding accompanied change dominant C–F...H–C arene ligands or 4.