Structural and kinetic investigations of group VI and group VIII metal carbonyl derivatives containing trisodium tris-m-sulfonatophenyl phosphine ligands /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1991.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Abstract: | Several group 6 carbonyl derivatives containing the trisodium tris-m-sulfanatophenyl phosphine (TPPTS) ligand have been synthesized as part of a kinetic investigation into the possible intramolecular interactions of these ligands. Kinetic studies into the dissociation of both the water-soluble, TPPTS ligand and its organic-soluble analog, PPh3, from M(CO)5L (M = Mo, W) complexes have been followed by in situ internal reflectance infrared spectroscopy. Kinetic measurements taken in water, THF, and mixtures of THF:H2O show the loss of phosphine to follow a first-order dependence on the metal substrate and zero order dependence on the incoming ligand (CO). Activation parameters determined for both Mo(CO)5TPPTS and W(CO)5TPPTS in 1:1 THF:H2O are ΔH[double dagger]= 28.0[plus or minus]1.3 and ΔS[double dagger]= -4.80[plus or minus]3.33, ΔH[double dagger]= 31.1[plus or minus]1.4 and ΔS[double dagger]= -1.20[plus or minus]3.4 kcal mol^-1 and eu, respectively. These values are compared to their analogous Mo(CO)5PPh3 and W(CO)5PPh3 activation parameters, showing only slight differences. A series of kinetics for the loss of a phosphine from cis-Mo(CO)4L2 complexes were carried out in 2-methoxyethanol under an atmosphere of CO and at temperatures between 50 to 80 °C. The activation parameters for the reaction of carbon monoxide with cis-Mo(CO)4[TPPTS]2, cis-Mo(CO)4[PPh3]2, and [Na-Kryptofix-221]6[cis-Mo(CO)4{P(m-C6H4SO3)3}2] were determined to be ΔH[double dagger]= 28.9[plus or minus]2.2 and ΔS[double dagger]= 12.2[plus or minus]6.7, ΔH[double dagger]= 28.8[plus or minus]0.34 and ΔS[double dagger]= 12.5[plus or minus]1.0, and ΔH[double dagger]= 26.3[plus or minus]1.8 and ΔS[double dagger]= 8.7[plus or minus]5.5 kcal mol^-1 and eu, respectively. Results of this study indicate a slight interaction between neighboring TPPTS ligands. Under similar conditions cis-W(CO)4L2 (L = TPPTS and PPh3) complexes were found to undergo exclusively intramolecular rearrangements to the corresponding trans species. This intramolecular rearrangement for both cis-W(CO)4 (TPPTS)2 and cis-W(CO)4[TPPTS]2 and cis-W(CO)4[PPh3]2 was determined to be a lower energy pathway than phosphine dissociation with activation numbers of ΔH[double dagger]= 19.0[plus or minus]3.9 and ΔS[double dagger]= -18.4[plus or minus]11.7 and ΔH[double dagger]= 17.7[plus or minus]1.2 and ΔS[double dagger]= -21.5[plus or minus]3.8 kcal mol^-1 and eu, respectively... |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Chemistry." |
| Physical Description: | xviii, 154 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |