Abstract
Abstract Treatment of the diamindopyridyl ligand, 4-Me-2,6-(HN-2,6-iPr2C6H3)2C5H3N, with WCl4(DME) (DME = dimethoxyethane) in the presence of 2 equiv of DBU (DBU=1,8-Diazabicyclo[5.4.0]undec-7-ene) gave the ditungsten complex, W2Cl4(μ-κ2-4-Me-2-(HN-2,6-iPr2C6H3)2-6-(N-2,6-iPr2C6H3)C5H2N)2 (1). NMR spectroscopy and X-ray studies showed that 1 have two amino arms and chloro groups point towards the protons of those two amino groups. We then reduced the bulk of the diamindopyridyl ligand by substituting Dep (2,6-Et2C6H3) for Dipp (2,6-iPr2C6H3), and the product W2Cl4(μ-κ2-4-Me-2-(HN-2,6-Et2C6H3)-6-(N-2,6-Et2C6H3)C5H2N)2 (2) structurally similar to 1 was isolated upon reacting with WCl4(DME). Subsequently, attempts to reduce 1 and 2 by KC8 were carried out. However, the reduced product of 1 decomposes rapidly in solutions, while the free ligand was the major product upon reduction of 2. In the second part of this thesis, we employed amidophosphinopyridiyl ligand 2-(HN-2,6-iPr2C6H3)-6-P(C6H5)2pyridine to stabilize metals. Treatment of CoCl2 or MnCl2 with (Et2O)Li[κ1-2-(N-2,6-iPr2C6H3)-6-P(C6H5)2C5H3N] yielded the mononuclear compounds (OEt2)Co[κ2-2-(N-2,6-iPr2C6H3)-6-P(C6H5)2C5H3N]2 (5) and (THF)Mn[κ2-2-(N-2,6-iPr2C6H3)-6-P(C6H5)2C5H3N]2 (6), respectively. Both metal centers adopt a square pyramidal configuration. The reaction between (Et2O)Li[κ1-2-(N-2,6-iPr2C6H3)-6-P(C6H5)2C5H3N] and CuI yielded the trinuclear complex IV (CuI)Cu2[μ3-κ1:κ2-2-(N-2,6-iPr2C6H3)-6-P(C6H5)2C5H3N]2 (7), where CuI is ligated by two phosphine groups. The structure of 7 is similar to the previously prepared tricopper complex Li{Cu3[μ-κ3-4-methyl-2,6-bis(N-2,6-iPr2C6H3)2pyridine]2}, in which three copper atoms are arranged in a linear conformation. Reduction of 7 gave the dicopper compound Cu2(μ-κ2-2-(N-2,6-iPr2C6H3)-6-P(C6H5)2C5H3N)2 (8) (vide infra), where each Cu is linear and ligated by two N atoms. Alternatively, compound 8 was isolated from the reaction of (Et2O)Li[κ1-2-(N-2,6-iPr2C6H3)-6-P(C6H5)2C5H3N] and CuI. Interestingly, treatment of 7 with Pd(PEt3)3, Ni(PEt3)4 and Fe2(CO)9 led to the formation of three heterotrinuclear complexes (PEt3)PdCu2[μ3-κ1:κ2-2-(N-2,6-iPr2C6H3)-6-P(C6H5)2C5H3N]2 (9), (PEt3)NiCu2[μ3-κ1:κ2-2-(N-2,6-iPr2C6H3)-6-P(C6H5)2C5H3N]2 (10) and (CO)3FeCu2[μ3-κ1:κ2-2-(N-2,6-iPr2C6H3)-6-P(C6H5)2C5H3N]2 (13), respectively. The conformation of these three heterotrinuclear complexes is roughly the same, in which Pd, Ni and Fe atoms replace the phosphine-bound CuI fragment. Notably, three metals in 13 are arranged in a linear mode. Although the iron center in 13 adopts a trigonal bipyrimidal conformation and three CO ligands are in equatorial positions, the angles between the three carbonyl groups are not equivalent; the angle close to the copper centers is larger than the other two. Reactions of 7 with 1 equivalent of LiNPh2 generateed the complex, (CuNPh2)Cu2[μ3-κ1:κ2-2-(N-2,6-iPr2C6H3)-6-P(C6H5)2C5H3N]2 (14), which reacted with bromobenzene via C-N coupling to give NPh3 upon ultraviolet radiation.