Conformational Heterogeneity in Diphthalocyaninato(2–)metallates(III) of Sc, Y, In, Sb, Bi, La, Ce, Pr, and Sm

Potassium diphthalocyaninato(2-)metallate(III), K[M(pc(2-))(2)] (M = Bi, La, Ce, Pr, Sm, Sb, In) has been prepared by melting the metal chloride, iodide or acetate with 1,2-dicyanobenzene in the presence of potassium methylate. Crystallisation with tetra(n-butyl)ammonium bromide or hydroxide (((Bu4N)-Bu-n)Br/OH), tetra(n-pentyl)ammonium chloride (((n)Pe(4)N)Cl) or bis(triphenylphosphine)iminium halide ((PNP)X; X = Br, I) yields the corresponding red-purple complex salt ((Bu4N)-Bu-n)[M(pc(2-))(2)] (M = Bi (1), La (3), Ce (2)), ((Bu4N)-Bu-n)[M(pc(2-))(2)] . xCH(3)OH (M = Bi (5), Pr (6), Sm (7); 0 less than or similar to x less than or similar to 1), ((n)Pe(4)N)[La(pc(2-))(2)] (4), ((Bu4N)-Bu-n)[Pr(pc(2-))(2)] . 2 py (10), ((Bu4N)-Bu-n)[Sb(pc(2-))(2)] . 2 thf (11), (PNP)(2)[M(pc(2-))(2)]Br . 2 Et2O (M = Sb (12), Bi (13)), and (PNP)(2)[In(pc(2-))(2)]I . 2 Et2O (14). Bronze coloured diphthalocyaninato(1-) metal(III) polyiodide, [M(pc(-))(2)]I-2 (M = Sc, Y) has been prepared similarly in the presence of ammonium iodide. Reduction with ((Bu4N)-Bu-n)OH provides ((Bu4N)-Bu-n)[M(pc(2-))(2)] . xCH(3)OH (M = Y (8), Sc (9); 0 less than or equal to x less than or equal to 1). Spectral properties (UV/VIS/NIR; IR; resonance Raman) of diphthalocyaninates in their different ring oxidation states (2-/2-; 2-/1-; 1-/1-) are discussed. 1-3 crystallise in the tetragonal (P4/ncc), 5-9 in the orthorhombic (Pna2(1)), 10, 11 in the triclinic (P-1), and 4, 12 14 in the monoclinic crystal system (4: P2(1)/m; 12: C2/c; 13, 14: P2/c). Ecliptic rotamers with skew angles ranging from 4.1 degrees to 6.0 degrees are found in 1-3, and staggered rotamers with skew angles ranging from 35.8 degrees to 45.0 degrees are found in 4-14. The mean M-N-i bond lengths and interplanar distances increase monotonically with the ionic radius of the metal ion. Both distances deviate notably from this linear correlation in the Sb-III. and Bi-III derivatives. The discrepancy is presumably due to the sterical dominance of the ns(2) lone-pair character. The actual size of eight co-ordinated Sb-III and Bi-III is estimated to be R-8 approximate to 1.02(Sb)/1.11(Bi) Angstrom. In every complex salt, the pc ligand is severely distorted from planarity and can adopt domed, saddled, waved and mixed non-planar conformations; the crystal symmetry is the most important factor for the conformational heterogeneity.