SYNTHESIS AND STRUCTURAL SYSTEMATICS OF NITROGEN BASE ADDUCTS OF GROUP-2 SALTS .4. SOME COMPLEXES OF GROUP-2 HALIDES WITH ETHANE-1,2-DIAMINE

Syntheses and room-temperature single-crystal X-ray structure determin ations are recorded for a number of adducts of ethane-1,2-diamine (en) with Group 2 metal salts, MX(2).n(en). [Mg(en)(3)]Br-2.MeOH (1) is mo noclinic, P2(1)/c, a 9.067(5), b 15.161(4), c 14.839(8) Angstrom, beta 121.86(5)degrees, Z=4 f.u.; R was 0.070 for N-o 1226 independent 'obs erved' (I > 3 sigma(I)) diffractometer reflections; [Mg(en)(3)]I-2.MeO H (2) is triclinic, <P(1)over bar>, a 11.500(2), b 9.527(6), c 8.825(4 ) Angstrom, alpha 106.30(4), beta 100.57(3), gamma 90.28(4)degrees, Z= 2 f.u.; R 0.045 for N-o 3562. In (1) and (2), [Mg-N] are 2.20 and 2.19 (2) Angstrom. [Ca(en)(4)]Br-2 (3) is orthorhombic, Fddd, a 28.54(1), b 15.863(7), c 8.927(9) Angstrom, Z=8 f.u.; Ca-N are 2.608(7) and 2.556 (8) Angstrom. [Sr(en)(4)]Cl-2.2MeOH (4) is also orthorhombic, Fddd, a 26.627(8), b 15.388(4), c 11.313(4) Angstrom, Z=8 f.u.; R 0.059 for N- o 535. [Sr(en)(4)]Br-2.2en (5) is tetragonal, I4(1)/a, a 9.215(7), c 2 7.678(3) Angstrom, Z=4 f.u., R 0.044 for N-o 657. [Sr(en)(4)]I-2.MeOH (6) is tetragonal, I4(1)/amd, a 9.389(1), c 28.78(1) Angstrom, Z=4. f. u., R 0.040 for N-o 510. 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) Angstrom. [ClBa(en)(3)(en )((2/2))]((infinity/infinity)) Cl(BaCl2.4en) (7) is monoclinic, P2(1), a 8.666(3), b 9.063(10), c 12.655(5) Angstrom, beta 108.13(3)degrees, Z=2 f.u., R 0.048 for N-o 1479. In (1) and (2), magnesium is six-coor dinate [Mg(N,N '-bidentate)(3)]; (3)-(6), calcium and strontium are ei ght-coordinate [M(N,N '-bidentate)(4)]; in (7), barium is nine-coordin ate, one of the en ligands being bridging so that the complex is a sin gle-stranded polymer generated by the 2(1) screw. Ba-Cl is 3.419(5) An gstrom, Ba-N bidentate en-N are 2.91(2)-2.97(3) Angstrom, and Ba-N mon odentate en-N 2.92(1), 3.15(1) Angstrom.