Two [Cu2I2]-based coordination polymers of 1,3-bis(pyridin-4-yl)propane

Abstract

Solvothermal reactions of Cu(2)(OH)(2)CO(3) with 1,3-bis(pyridin-4-yl)propane (bpp) in the presence of aqueous ammonia in 4-iodotoluene/CH(3)CN or 1,4-diiodobenzene/CH(3)CN afforded two [Cu(2)I(2)]-based coordination polymers, namely catena-poly[[[di-μ-iodido-dicopper(I)]-bis[μ-1,3-bis(pyridin-4-yl)propane-κ(2)N:N']] p-toluidine tetrasolvate], {[Cu(2)I(2)(C(13)H(14)N(2))(2)]·4C(7)H(9)N}(n), (I), and the analogous 1,4-diiodobenzene monosolvate, {[Cu(2)I(2)(C(13)H(14)N(2))(2)]·C(6)H(4)I(2)}(n), (II). The [Cu(2)I(2)] unit of (I) lies on a centre of symmetry at the mid-point of the two I atoms, while that of (II) has a twofold axis running through the I···I line. In (I) and (II), each Cu centre is tetrahedrally coordinated by two μ-I and two N atoms from two different bpp ligands. Each rhomboid [Cu(2)I(2)] unit can be considered as a four-connecting node linked to the symmetry-related [Cu(2)I(2)] units via two pairs of bpp ligands to form a one-dimensional double chain along the c axis. The dimensions of the [Cu(2)I(2)(bpp)(2)](2) rings in (I) and (II) are different, which may be due to the presence of different guest solvent molecules in the structures. In (I), one p-toluidine molecule, derived from an Ullmann coupling reaction of 4-iodotoluene with ammonia, interacts with the [Cu(2)I(2)] cluster fragment through N-H···I hydrogen bonds, while the two p-toluidine molecules interact via N-H···N hydrogen bonds. In (II), two I atoms of each 1,4-diiodobenzene molecule are linked to the I atoms of the [Cu(2)I(2)] fragments from a neighbouring chain via I···I secondary interactions.