SYNTHESIS AND STRUCTURAL SYSTEMATICS OF NITROGEN BASE ADDUCTS OF GROUP-2 SALTS .6. MIXED OLIGODENTATE-ALIPHATIC-BASE OXYGEN LIGAND ADDUCTS

In the course of synthesizing oligodentate aliphatic nitrogen base add ucts of Group 2 metal salts, a number of mixed-ligand species have bee n isolated with oxygen ligands, and characterized by room-temperature single-crystal X-ray studies. BaCl2.4en.H2O =[(en)(4)Ba(OH2)]Cl-2 (1) is monoclinic, P2(1)/c, a 9.456(4), b 14.953(6), c 14.82(1) Angstrom, beta 100.78(6)degrees, Z=4 f.u., R 0.043 for N-o 1862 independent 'obs erved' (I > 3 sigma(I)) diffractometer reflections. Ba-N range between 2.900(9) and 2.97(1)Angstrom, and Ba-O is 2.779(8)Angstrom in the nin e-coordinate BaN8O environment. CaCl2.2dien.H2O=[[dien)(2)Ca(OH2)Cl]Cl (2) is monoclinic, P2(1)/c, a 10.808(4), b 11.999(4), c 15.71(1)Angst rom, beta 123.58(4)degrees, Z=4 f.u., R 0.050 for N-o 3134; CaBr2.2die n.2H(2)O=[(dien)(2)Ca(OH2)(2)] Br-2 (3) is monoclinic, P2(1)/c, a 18.0 01(3), b 11.983(6), c 21.562(5) Angstrom, beta 124.97(2)degrees, Z=8 f .u., R 0.045 for N-o 2858; CaBr2.2dien.2MeOH=[(dien)(2)Ca(HOMe)(2)] Br -2 (4) is orthorhombic, P2(1)2(1)2(1), a 16.620(8), b 12.78(1), c 9.76 5(4) Angstrom, Z=4 f.u., R 0.073 for N-o 878. In (2)-(4), the cation c onfigurations are similar, being of the form [L(2)Ca(dien)(2)], L (L') being the unidentate ligand, with the eight-coordinate calcium enviro nments [L(2)Ca(N-3)(2)] in a common isomeric configuration, the two li gands L being cis in an array of quasi-2 symmetry. Ca-Cl in (2) is 2.8 34(1)Angstrom; Ca-N generally range between 2.52(5) and 2.64(1)Angstro m; Ca-O(H2O) is 2.418(2) in (2), 2.434(7)-2.496(7)Angstrom in (3), whi le Ca-O(MeOH) in (4) are 2.43(2) and 2.43(2)Angstrom. [Mg(HOMe)(6)]I-2 .2tmeda (5) (tmeda= Me(2)N(CH2)(2)NMe(2)), orthorhombic, Pbca, a 23.42 3(8), b 15.306(4), c 9.345(1) Angstrom, Z=4 f.u., R 0.052 for N-o 1928 , provides a usefully precise description for the centrosymmetric cati on, Mg-O being 2.069(4), 2.080(4), 2.096(5) Angstrom, with Mg-O-C 128. 4(4) 128.9(4), 129.7(4)degrees. [(tmeda)SrI2(HOMe)(3) .(1/2)tmeda (6), monoclinic, P2(1)/c, a 7.730(1), b 35.493(9), c 11.081(2) Angstrom, b eta 126.49(1)degrees, R 0.042 for N-o 3161, has a seven-coordinate, qu asi-pentagonal bipyramidal SrN2I2O3 array about the metal with trans-i odines.