Lewis-Base Adducts of Group 11 Metal(I) Compounds. XL. Conformational Systematics of [(N-base)1(CuX)₁]_∞ Orthogonal' Stair' Polymers (N-base = 'One-Dimensional Aceto-nitrile, Benzo-nitrile Ligand)

Abstract

The structural chemistry of the polymeric 1:1 adducts of copper(1) halides ( CuX ; X = Cl, Br, I) with nitrile bases (exemplified by aceto- and benzo-nitrile ) has been systematically explored. Single-crystal X-ray structure redeterminations of enhanced precision have been carried out for all acetonitrile adducts (refined as orthorhombic, Pbnm , Z 4, a ≈ 13.0, b ≈ 8.5, c ≈ 4.0 Å ; R 0.039, 0.030, 0.043 for N_o = 534, 365, 727 'observed' reflections) and the chloride and bromide benzonitrile adducts (monoclinic, P2₁/n, a ≈ 3.9, b ≈ 17.5, c ≈10.9 Å , β ≈ 98, Z 4); R 0.046, 0.048 for N_o = 1452, 1209); all structures are of the common one-dimensional 'stair' polymer type. In these adducts, the ligand is essentially 'one-dimensional' with substituents well removed from the point of attachment and from interaction within the parent polymer chain. Under these circumstances, the polymer is essentially 'orthogonal' with Cu-X crosslinks at (or nearly at) right angles to the polymer axis, and containing quasi-mirror planes, the series providing reference parameters for the description of distortions observed in these polymers when more hindered bases are coordinated.