Synthesis and Structural Systematics of Nitrogen Base Adducts of Group 2 Salts. V. Some Complexes With 3-Azapentane-1,5-diamine

Abstract

Syntheses and room-temperature single-crystal X-ray structural characterizations are recorded for an array of adducts of H₂N(CN₂)₂NH(CH₂)₂NH₂, ' dien ', with salts of Group 2 elements, MX₂.n( dien ).[Mg( dien )₂] Cl₂ (1) is monoclinic, P 2₁/c, a 11.326(6), b 10.928(5), c 12.636(6) Ǻ, β 92.74(4)°, Z = 4 f.u .; R was 0.047 for No 1726 independent 'observed' (I > 3σ(I)) diffractometer reflections. [Mg( dien )₂] Br₂ (2) is monoclinic, P 2₁/c, a 9.541(7), b 14.55(1), c 11.894(8) Ǻ, β 100.42(5)°, Z = 4 f.u ., R 0.054 for No 1778. [Mg( dien )₂] I₂ (3) is isomorphous , a 9.969(2), b 14.907(2), c 12.300(3) Ǻ, β 100.02(2)°, R 0.039 for No 3180. In all three complexes, the two tridentate ligands are disposed mer in a six-coordinate MgN₆ environment, the trans Mg-N(central) distances being somewhat shorter (2.161 (4)-2.181(9)Ǻ) than Mg-N(distal) (2.215(8)-2.249(4)Ǻ). [Ba(dien)₃] Cl₂ (4a) is orthorhombic, Pnaa , a 19.309(2), b 13.545(2), c 8.872(2)Ǻ, Z = 4 f.u ., R 0.055 for No 1070; the methanol disolvate (4b) is monoclinic, P 2₁/c, a 16.807(8), b 8.764(5), c 19.493(4) Ǻ, β 102.39(3)°, Z = 4 f.u ., R 0.11 for No 2613. A family of derivative structures (5)-(8), [M( dien )₃] X₂, M, X = Sr , Br (5), Sr , I(6), Ba , Br (7), Ba , I(8), have cells of half the volume (a ≈ 13.8, b ≈ 9, c ≈ 9.8 Ǻ), probable space group P2₁2₁2, R 0.050, 0.061, 0.034, 0.037 for No 549, 914, 1044, 1801 respectively, with the cations disposed about crystallographic 2 axes with one disordered ligand . [ Ba( dien )₃](ClO₄)₂ (9) is rhombohedral , R3c, a 10.240(2), c 45.19(1) Ǻ (hexagonal setting), Z = 6 f.u ., R 0.054 for No 508. Like (4)-(8), the barium environment is nine-coordinate with the three tridentate ligands here  disposed about a 3 axis through the metal.