Conformational flexibility of the di(1,3-diaminopropane)copper(II) cation Part 3. Structure determination for trans-diaquabis(1,3-diaminopropane-N,N′)copper(II)trans-di(ortho-phthalato-O)bis(1,3-diaminopropane-N,N′)cuprate(II) monohydrate and DFT calculations for the trans-diaquabis(1,3-diaminopropane-N,N′)copper(II) cation2

Abstract

Abstract The structure of trans-diaquabis(1,3-diaminopropane-N,N′)copper(II)trans-di(ortho-phthalato-O)bis(1,3-diaminopropane-N,N′)-cuprate(II) dihydrate was determined by single crystal X-ray diffraction methods. The compound crystallises in the triclinic system, space group P 1 (No. 2) with a = 7.233(2), b = 10.187(2), c = 12.905(2) A , α = 81.70(2), β = 82.08(2) and γ = 81.03(2)°, and V = 922.8(3) A 3 . The structure consists of cationic and anionic monomeric coordination units and a crystal water molecule. Both of the coordination units contain a centrosymmetric [Cu(tn)2]2γ moiety (tn = 1,3-diaminopropane). In the cationic unit the axial sites are occupied by water molecules, whereas in the anionic unit there are doubly deprotonated ortho-phthalate anions in the axial positions. The respective CuO bond lengths are quite long, 2.618(2) and 2.622(2) A. The six-membered chelate rings formed by the CuII ion and in display a chair conformation. In the anionic complex unit the rings are less puckered. The geometry of the cationic species was optimised by DFT methods and it was found to be more stable than a five-coordinated species with a non-coordinated water by 77.4 kJ mol−1.