Synthesis and Structural Systematics of Nitrogen Base Adducts of Group 2 Salts. IV. Some Complexes of Group 2 Halides With Ethane-1,2-diamine

Abstract

Syntheses and room-temperature single-crystal X-ray structure determinations are recorded for a number of adducts of ethane-1,2-diamine (en) with Group 2 metal salts, MX₂.n(en). [Mg(en)₃] Br₂.MeOH (1) is monoclinic, P 2₁/c, a 9.067(5), b 15.161(4), c 14.839(8) Ǻ, β 121.86(5)°, Z = 4 f.u .; R was 0.070 for No 1226 independent 'observed' (I > 3σ(I)) diffractometer reflections; [Mg(en)₃] I₂.MeOH (2) is triclinic, Pī , a 11.500(2), b 9.527(6), c 8.825(4) Ǻ, α 106.30(4), β 100.57(3), γ 90.28(4)°, Z = 2 f.u .; R 0.045 for No 3562. In (1) and (2), (Mg-N) are 2.20 and 2.19 Ǻ. [Ca(en)₄]Br₂ (3) is orthorhombic, Fddd , a 28.54(1), b 15.863(7), c 8.927(9) Ǻ, Z = 8 f.u .; Ca-N are 2.608(7) and 2.556(8) Ǻ. [ Sr (en)₄] Cl₂.2MeOH (4) is also orthorhombic, Fddd , a 26.627(8), b 15.388(4), c 11.313(4) Ǻ, Z = 8 f.u .; R 0.059 for No 535. [ Sr (en)₄] Br₂.2en (5) is tetragonal, I 4₁/a, a 9.215(7), c 27.678(3) Ǻ, Z = 4 f.u ., R 0.044 for No 657. [ Sr (en)₄]I₂.MeOH (6) is tetragonal, I4₁/amd, a 9.389(1), c 28.78(1) Ǻ, Z = 4. f.u ., R 0.040 for N_o 10. In (4), (5) and (6), Sr -N are 2.728(7), 2.718(7); 2.720(7), 2.703(7) and 2.75(2), 2.72(7) Ǻ. [ ClBa (en)3(en)(2/2)](∞ ׀ ∞) Cl (≡ BaCl₂.4en) (7) is monoclinic, P 2₁, a 8.666(3), b 9.063(10), c 12.655(5) Ǻ, β 108.13(3)°, Z = 2 f.u ., R 0.048 for N_o 1479. In (1) and (2), magnesium is six-coordinate [Mg(N,N'- bidentate )3]; (3)-(6), calcium and strontium are eight-coordinate [M(N,N'- bidentate )₄]; in (7), barium is nine-coordinate, one of the en ligands being bridging so that the complex is a single-stranded polymer generated by the 2₁ screw. Ba-Cl is 3.419(5) Ǻ, Ba -N bidentate en-N are 2.91(2)-2.97(3) Ǻ, and Ba -N monodentate en-N 2.92(1), 3.15(1) Ǻ.