| Chapter 1. The known ligands HC(pz)3, HC(3,5-Me 2pz)3, HC(3-Phpz)3, and HC(3-Butpz) 3 and the new ligand HC(3-Pripz)3 (pz = pyrazolyl ring) are prepared in CHCl3/H2O using the appropriate pyrazole, an excess of Na2CO3, and tetra-n-butylammonium bromide as the phase transfer catalyst. Using these conditions, good yields of the ligands are consistently obtained. The new ligand PhC(pz)2py (py = pyridyl ring) is prepared in the CoCl2 catalyzed condensation reaction of (pz)2S=O and Ph(py)C=O. The reaction of HC(pz) 3, KOBut and para-formaldehyde followed by quenching with water yields HOCH2C(pz)3. All of these ligands, except HC(3-Butpz)3, react with [Mn(CO)5]SO 3CF3, prepared in situ from Mn(CO) 5Br and Ag(SO3CF3), to yield the respective [(ligand)Mn(CO) 3]SO3CF3 complex. The carbonyl stretching frequencies and 13C NMR trends of these complexes indicate that the donor abilities of all of the ligands are fairly similar. The solid state structure of {lcub}[HC(3-Pripz)3]Mn(CO)3 {rcub}+ shows the HC(3-Pripz) 3 ligand is iridentate with the iso-propyl groups rotated away from the Mn(CO)3 core of the cation relieving any possible steric congestion.; Chapter 2. The reaction of either HC(pz)3, HC(3,5-Me2pz)3, HC(3-Phpz)3, or a 4:1 HC(3- i-Prpz)3/HC(3-i-Prpz)2(5- i-Prpz) mixture (pz = pyrazolyl ring) and Re(CO)5Br results in the formation of {lcub}[HC(pz)3]Re(CO)3{rcub}Br (1), {lcub}[HC(3,5-Me2pz)3]Re(CO)3{rcub}Br (3), {lcub}[HC(3-Phpz)3]Re(CO)3{rcub}Br (4), {lcub}[HC(3- i-Prpz)3]Re(CO)3{rcub}Br (5), and {lcub}[HC(3- i-Prpz)2(5-i-Prpz)]Re(CO)3{rcub}Br (6). The reaction of PhC(pz)2(py) (py = pyridyl ring) and Re(CO)5Br yields {lcub}[PhC(pz)2(py)]Re(CO)3{rcub}Br (9) while a reaction of Re(CO)5Br and 1,4-C6 H4[CH2OCH2C(pz)3]2 in a 2:1 mol ratio gives {lcub}1,4-C6H4[CH2OCH 2C(pz)3]2 [Re(CO)3]2{rcub}(Br) 2 (10). The reaction of Re(CO)5Br and AgBF 4 followed by addition of either HC(pz)3 or the 4:1 HC(3- i-Prpz)3/HC(3-i-Prpz)2(5- i-Prpz) mixture results in the preparation of {lcub}[HC(pz)3]Re(CO) 3{rcub}BF4 (2), {lcub}[HC(3-i-Prpz) 3]Re(CO)3)BF4 (7), and {lcub}[HC(3- i-Prpz)2(5-i-Prpz)]Re(CO)3{rcub}BF 4 (8), respectively. The carbonyl stretching frequencies in all of these complexes are similar, with the exception of 9, which has much lower values. The methine hydrogen atoms of compounds 1, 5, and 6 show deshielded chemical shift values as a result of hydrogen bonding interactions with the bromide counterion. The solid state structures of the iso... |
