Design of a New Reactive Phase using Ammonia as an Ancillary Ligand: Structure and Reactivity of Diamminebis(propynoato)zinc

Abstract

Addition of a 2M solution of NH₃ in ethanol to solid tetraaquabis(propynoato)zinc 1 leads directly to the title complex 2. Formation of hydroxides is eliminated using this procedure. The structure of 2 differs markedly from the octahedral structure observed for the analogous octahedral aqua complex 1. The structure of 2 is monomeric and tetrahedral, with monodentate carboxylate ligands. The crystal structure consists of isolated molecules interconnected by two strong N-H…O hydrogen bonds and one C-H…O hydrogen bond. Infinite sets of short-C≡C-…-C≡C-contacts are also present in the crystal structure. Accordingly. ⁶⁰Co γ-irradiation of 2 leads to the analogous dark brown polypropynoate complex.

Key Words:

• Metal carboxylates
• solid-state reaction