Darstellung und Struktur dreier verschiedener Bis(ethylendiamin)-kupfer(II)-tetraborate / Preparation and Structure of Three Different Bis(ethylenediamine) Copper(II) Tetraborates

Abstract

Three different bis(ethylenediamine) Copper(II) tetraborates have been prepared: Cu(en) 2 [B 4 O 5 (OH) 4 ] · 2B(OH) 3 (A), 2{Cu(en) 2 B(OH) 3 · H 2 O[B 4 O 5 (OH) 4 ]} · H 2 O (B) and {Cu(H 2 O) 2 [B 4 O 5 (OH) 4 ] 2 }(μ-H 2 O){Ag(en) 2 } · (μ-H 2 O){Na(H 2 O) 2 ) (C). The crystal structure analyses of A (monoclinic, P2 1 /c, a = 1282.5(1), b = 1020.8(1), c = 1510.5(2) pm; β = 96.66(1)°, Z = 4), B (monoclinic, Pc, a = 1254.4(1), b = 914.1(1), c = 1594.2(2) pm; β = 94.79(1)°, Z = 2) and C (triclinic, P1, a = 846.3(3), b = 917.9(3), c = 928.1(7) pm; α = 93.71(6)°, β = 104.79(3)°, γ = 103.23(2)°; Z = 1) show that all compounds contain the tetraborate ion [B 4 O 5 (OH) 4 ] 2- . In A and B, there are tetraborate ions and boric acid molecules. The coordination sphere of the Cu 2+ ion is Jahn-Teller distorted, coordinated by 2 en groups with 4 Cu-N distances between 196 and 206 pm, as well as by 2 OH groups with Cu-O distances of 251 to 274 pm. In C, the Cu 2+ ion is surrounded by 6 OH groups, and the Ag + ion by 2 en and 2μ-H 2 O molecules.