51141-11-8Relevant academic research and scientific papers
Tetracyanoquinodimethane salts of transition-metal complexes. Crystal and molecular structures and magnetic properties of tris(1,10-phenanthroline)zinc(II) bis(tetracyanoquinodimethanide) and tris(1,10-phenanthroline)copper(II) bis(tetracyanoquinodimethanide)
Bencini, Alessandro,Midollini, Stefano,Zanchini, Claudia
, p. 1963 - 1969 (2008/10/08)
The compounds tris(1,10-phenanthroline)zinc(II) bis(tetracyanoquinodimethanide), Zn(phen)3(TCNQ)2 (1), and tris(1,10-phenanthroline)copper(II) bis(tetracyanoquinodimethanide), Cu(phen)3(TCNQ)2 (2), were synthesized and their crystal structures solved at room temperature. They crystallize in the triclinic system, space group P1. The lattice constants for Zn(phen)3(TCNQ)2 are a = 2197.2 (5) pm, b = 1116.4 (3) pm, c = 1016.5 (3) pm, α = 86.03 (4)°, β = 84.81 (6)°, and γ = 83.36 (3)°, and those for Cu(phen)3(TCNQ)2 are a = 2194.5 (5) pm, b = 1110.6 (3) pm, c = 1018.6 (3) pm, α = 86.50 (5)°, β = 84.41 (6)°, and γ = 83.21 (4)°. Least-squares refinement of the structures leads to conventional R factors of 0.060 and 0.064 for 1 and 2, respectively. The asymmetric units of 1 and 2 are formed by [M(phen)3]2+ cations (M = Zn, Cu) and two crystallographically independent TCNQ- anions, called A and B, respectively, not directly bound to the metals and rather different from each other. The A anions form dimeric units with a ring-to-external-bond (R-B) overlap, while the B molecules arrange themselves to form rather unusual discrete dimers, with an external-bond-to-external-bond overlap (B-B mode). The temperature dependences of the magnetic susceptibilities for 1 and 2 indicate that a magnetic coupling occurs, and the χM values suggest that one of the two crystallographically independent dimers seen in the crystal structures is essentially diamagnetic also at room temperature.
