## LSU Historical Dissertations and Theses

1997

Dissertation

#### Degree Name

Doctor of Philosophy (PhD)

Chemistry

#### First Advisor

Andrew W. Maverick

#### Abstract

The brick-red ferrocenophene 1,4-(3,3$\sp\prime$-bis(1,1-dimethylpentyl)-1,1$\sp\prime$-ferrocenediyl) -1,3-butadiene was prepared via a six-step synthetic route. It was isolated and characterized for use as a monomer in Ring Opening Metathesis Polymerization. Fluorescent molybdenum(V)-oxo complexes such as $\rm MoOCl\sb4(H\sb2O)\sp-$ undergo thermal and photochemical reactions with the series of phosphines $\rm PEt\sb2,\ PEt\sb3Ph,\ PEtPh\sb2$ and PPh$\sb3$ as oxygen atom acceptors. PEt$\sb3$ reacts spontaneously to form several products: $\rm (PPh\sb4)\lbrack MoCl\sb4(PEt\sb3)\sb2\rbrack,\ (PPh\sb4)\sb2\lbrack MoOCl\sb5\rbrack{\cdot}2CH\sb2Cl\sb2,$ and a maroon oil that contains $\rm OPEt\sb3,\ MoOCl\sb2(PEt\sb3)\sb3$ and $\rm MoCl\sb4(PEt\sb3)\sb2.$ Both $\rm (PPh\sb4)\lbrack MoCl\sb4(PEt\sb3)\sb2\rbrack$ and OPEt$\sb3$ are products of an oxygen atom transfer reaction. PEt$\sb2$Ph and PEtPh$\sb2$ also produce the corresponding phosphine oxides, but only under irradiation. The molybdenum(III) complex $\rm MoCl\sb3(OPEt\sb2Ph)\sb2(PEt\sb2Ph)$ was isolated from irradiated Mo(V)-PEt2Ph solutions. PPh$\sb3$ is not oxidized under these conditions. Selective irradiation of the longer-wavelength molybdenum(V) absorption bands leads to similar photoredox reactions, but much more slowly. The electronic absorption spectra of the irradiated Mo(V)-PEtPh$\sb2$ and Mo(V)-PPh$\sb3$ solutions are similar to those of the known oxomolybdenum(V) complex MoOCl$\sb3$(dppe), whose X-ray crystal structure is also reported. The spectroscopic and photochemical properties of these species were also compared with those of the known oxomolybdenum(IV) complexes MoOCl(dppe)$\sb2\sp+$ (dppe = 1,2-bis(diphenylphosphino)ethane) and MoOCl(CN-t-Bu)$\sb4\sp+$ and the new dimethoxymolybdenum(IV) complex $\rm Mo(OCH\sb3)\sb2$(CN-t-Bu)$\sb4\sp{2+}.$ All three of these compounds are luminescent in the solid state at room temperature and at 77 K, with MoOCl(CN-t-Bu)$\sb4\sp{+}$ also exhibiting luminescence in $\rm CH\sb2Cl\sb2$ solution at room temperature. Luminescence lifetimes are $>$1 $\mu$s for all three complexes; the transition is assigned as phosphorescence, $\rm\sp3E\lbrack(d\sb{xy})\sp1(d\sb{xz,yz})\sp1\rbrack\to\sp{1A}\sb1\lbrack(d\sb{xy})\sp2\rbrack(C\sb{4v}).$.

9780591458848

105

COinS