Structural Aspects of Cu(I)(κ2-X1,X2)(Y3) and Cu(I)(η2-X1,X2)(Y3) Complexes

Structural parameters for over seventy complexes of the composition Cu(η2-X1×2)(Y3) or Cu(κ2-X1X2)(Y3) were analyzed in this work, being the third of a series of structural studies on three coordinated copper(I) complexes. Bidentate (X1X2) with monodentate (Y3) donor ligands build up distorted trigonal planar coordination spheres around copper(I) atoms. The bidentate ligands (X1X2) create three-, four-, and five-membered metallocyclic rings. The three-membered are: -C1-C2-Cu-C3; -B1=B2-Cu-Cl3; -P≡C2-Cu-C3, -B1-B2-Cu-X3, and B1-C2-Cu-C3. The X1-Cu-X2 angles indicate a total mean value of 44.2°. The four-membered complexes are -H1-B(H2)-H2-Cu-C3; -H1-B(Ph2)-H2-Cu-C3; -O1AlO2-Cu-N3; -O1CeO2-Cu-N3; -S1CP2-Cu-C3; -N1PN2-Cu-C3; -N1PS2-Cu-P3; -N1SiO1-Cu-Cl3; --N1CS2-Cu-C3; -Si1-NSi2-Cu-C3, and O1CO2-Cu-C3, and show a total mean value of the L-Cu-L angles of 71.0°. The five-membered are: -N1-C=C-N2-Cu-Y3 (more common) and N=C-C=N-Cu-C3. In this group, there are also copper(I) complexes in which the central Ns of five-membered metallocycle are “interlocked” in macrocycles. The X1-Cu-X2 angles exhibit an average value of 82.9°. There is a wide variety of monodentate (Y3) ligands in the studied complexes. The mean value of Cu-Y3 elongates with covalent radius (Å) of coordinate atoms in the sequence: 1.846(13) Å (N3, 0.75) < 1.884(21) Å (O3, 0.73) < 1.928(18) Å (C3, 0.77) < 2.126(18) Å (Cl3, 0.99) < 2.140(5) Å (S3, 1.02) < 2.194(4) Å (P3, 1.06) < 2.246(12) Å (Br3, 1.14) < 2.2445(18) Å (I3, 1.33). The data show that angular distortion from regular trigonal geometry grows in the following order: five-, four-, and three-membered.