USE OF TETRADENTATE (N2O2) LIGANDS TO FORM MONOMERIC, TRIMETALLIC GALLIUM COMPLEXES

Members of the SalanH(4) class of tetradentate (N2O2) ligand, N,N'-bis(o-hydroxybenzyl)1,2-diaminoethane (SaleanH(4)), N,N'-bis(o-hydroxybenzyl)-1,3-diaminopropane (SalpanH(4)), N,N'-bis(o-hydroxybenzyl)-1,2-diaminobenzene (SalophanH(4), and N,N'-bis(o-hydroxybenzyl)1,2-diamino-4,5-dimethylbenzene (SalomphanH(4)), react with 3 equiv of GaMe(3) to form the trimetallic complexes SaleanGaMe(GaMe(2))(2) (1), SalpanGaMe(GaMe(2))(2): (2), SalophanGaMe(GaMe(2))(2) (3), and SalomphanGaMe(GaMe(2))(2) (4). Similar reactions of the SalanH(4) ligands with GaEt(3) form SaleanGaEt(GaEt(2))(2) (5), SalpanGaEt(GaEt(2))(2) (6), SalophanGaEt(GaEt(2))(2) (7), and SalomphanGaEt(GaEt(2))(2) (8). For these compounds, the H-1 NMR data indicate the presence of rigid solution state geometries. A crystallographic study of 1, 2, and 5 demonstrates that the molecules contain a central GaR group (R = Me, Et) which is coordinated in a planar array to the nitrogens and oxygens of the ligand. The remaining GaR(2) groups each bridge an oxygen and nitrogen atom. Compound 1 contains one molecule of toluene as solvent of crystallization. Crystal data are as follows. 1: C28H39Ga3N2O2, space group P2(1)/c (no. 14), with a = 10.694(2) Angstrom, b = 14.101(2) Angstrom, c = 19.184(2) Angstrom, beta = 94.040(10)degrees, V = 2885.5(7) Angstrom(3), and Z = 4. With 316 parameters refined on 2615 reflections having F > 4.0 sigma(F), the final R values were R = 0.0498 and R(w) = 0.0545. 2: C22H33Ga3N2O2, space Group P2(1)/c (no. 14), with a = 16.247(12) Angstrom, b = 9.588(9) Angstrom, c = 17.131(8) Angstrom, beta = 116.21(4)degrees, V = 2395(3) Angstrom(3) and Z = 4. With 262 parameters refined on 1777 reflections having F > 6.0 sigma(F), the final R values were R = 0.0690 and R(w) = 0.0763. 5: C26H41Ga3N2O2, space group monoclinic P2(1)/n (no. 14), with a = 8.433(1) Angstrom, b = 22.010(2) Angstrom, c = 15.241(1) Angstrom, beta = 98.81(1)degrees, V = 2795.4(5) Angstrom(3), and Z = 4. With 298 parameters refined on 2111 reflections having F > 4.0 sigma(F), the final R values were R = 0.0458 and R(w) = 0.0492.