Determination of phosphine basicity and study of nucleophilic addition to [pi]-hydrocarbon ligands

dc.contributor.advisor Robert J. Angelici Bush, Russell
dc.contributor.department Chemistry 2018-08-17T10:54:15.000 2020-07-02T06:08:05Z 2020-07-02T06:08:05Z Thu Jan 01 00:00:00 UTC 1987 1987
dc.description.abstract <p>It has been recognized for some time that many low valent transition metal complexes can act as Lewis bases. Unlike organic bases, metal complexes have not been systematically investigated to determine what factors might influence their electron donating ability;As part of an effort to study metal complex basicity, titration calorimetry has been employed to determine the heats of protonation ([delta]H[subscript] HP's) of several phosphines commonly encountered in metal complexes. The phosphines are protonated with CF[subscript]3SO[subscript]3H in 1,2-dichloroethane solvent. The [delta]H[subscript] HP values are direct and accurate measures of phosphine basicity, and the method can be extended to basicity determination over a wide range of base strength;The ability to activate [pi]-hydrocarbon ligands toward nucleophilic attack is another important characteristic of transition metals. This feature has been extensively exploited in both large scale industrial processes and laboratory scale syntheses. Reactivity of the [pi]-hydrocarbon ligand in transition metal complexes can vary widely with changes in the nature of the metal or ancillary ligands; attempts to correlate the observed reactivity with experimentally determined parameters have previously been unsuccessful;A new method for predicting the reactivity of coordinated ethylene and benzene toward nucleophilic addition is described in this work. This scheme employs metal carbonyl C-O force constants to gauge the activating ability of a metal-ligands fragment to which ethylene or benzene is bound. The approach has proven quite capable of correlating the reactivity of numerous complexes with nucleophiles;In a related study, the activating ability of a metal carbonyl moiety was used to promote addition of a metal-based nucleophile to coordinated cycloheptatriene. The anion Re(CO)[subscript]5[superscript]- reacts with ([eta]-C[subscript]7H[subscript]8)Mn(CO)[subscript]3[superscript]+ to give the bimetallic complex, (1-5-[eta]-6-exo-Re(CO)[subscript]5-C[subscript]7H[subscript]8) Mn(CO)[subscript]3. This is the first example of metal carbonyl anion addition to a coordinated cyclic [pi]-hydrocarbon.</p>
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dc.identifier archive/
dc.identifier.articleid 9620
dc.identifier.contextkey 6342961
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath rtd/8621
dc.language.iso en
dc.source.bitstream archive/|||Sat Jan 15 02:14:34 UTC 2022
dc.subject.disciplines Inorganic Chemistry
dc.subject.keywords Chemistry
dc.subject.keywords Inorganic chemistry
dc.title Determination of phosphine basicity and study of nucleophilic addition to [pi]-hydrocarbon ligands
dc.type article
dc.type.genre dissertation
dspace.entity.type Publication
relation.isOrgUnitOfPublication 42864f6e-7a3d-4be3-8b5a-0ae3c3830a11 dissertation Doctor of Philosophy
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