Coordination Networks ofC3vandC2vPhenylacetylene Nitriles and Silver(I) Salts: Interplay of Ligand Symmetry and Molecular Dipole Moments in the Solid State

Five organic ligands of C 3 v and C 2 v symmetry, 3,5-bis(4-cyanophenylethynyl)cyanobenzene ( 1 ), 3,5-bis(4-cyanophenylethynyl)-4-methoxycyanobenzene ( 2 ), and 4,4‘-dicyanobenzophenone ( 3 ), cyanotris(4-cyanophenyl)methane ( 4 ), and tris(4-cyanophenyl)methanol ( 5 ), have been prepared, crystallized with silver(I) salts, and characterized by single-crystal X-ray study. Crystallographic data are as follows: [Ag· 1 ·CF 3 SO 3 ]·2C 6 H 6, triclinic, P 1̄ (no. 2), a = 10.0864(6) Å, b = 13.6029(10) Å, c = 13.8822(12) Å, α = 108.743(6)°, β = 95.063(6)°, γ = 95.484(5)°, Z = 2; [Ag· 2 ·CF 3 SO 3 ]·1.75C 6 H 6, triclinic, P 1̄ (no. 2), a = 14.6273(14) Å, b = 15.161(2) Å, c = 17.010(2) Å, α = 85.481(7)°, β = 65.745(5)°, γ = 80.283(9)°, Z = 4; [Ag· 3 ·CF 3 SO 3 ], triclinic, P 1̄ (no. 2), a = 8.8148(8) Å, b = 10.5031(6) Å, c = 10.8323(11) Å, α = 81.782(6)°, β = 67.448(8)°, γ = 66.501(5)°, Z = 2; [Ag· 4 ]BF 4 ·1.5C 6 H 6, monoclinic, C 2/ c (no. 15), a = 18.0187(4) Å, b = 14.9717(3) Å, c = 23.5469(5) Å, β = 105.5641(8)°, Z = 8; [Ag· 5 ·CF 3 SO 3 ]·2C 6 H 6, monoclinic, P 2 1 / n (no. 14), a = 10.230(2) Å, b = 11.839(2) Å, c = 26.071(4) Å, β = 90.589(8)°, Z = 4; [Ag· 2 ·CF 3 SO 3 ]·2C 6 H 6, triclinic, P 1̄ (no. 2), a = 14.4951(2) Å, b = 16.5954(1) Å, c = 17.0387(1) Å, α = 84.360(1)°, β = 79.728(1)°, γ = 73.118(1)°, Z = 4. Τ he crystal structures are similar to those previously found for the T d and D 3 h phenyl nitriles with Ag(I) salts and can be related to the diamond and graphite topologies. However, due to the intrinsic symmetry of C 3 v and C 2 v ligands, permanent molecular dipole moments are always present. The stacking sequences found in three graphite-like structures are in an antiparallel fashion so that the net dipole moments of the crystals are zero. Similarly, the diamond-like structure is composed of two interpenetrating diamondoid nets oriented in such a way that the net dipole moment of the two nets combined is zero.