Year of Publication

2012

Degree Name

Doctor of Philosophy (PhD)

Document Type

Doctoral Dissertation

College

Arts and Sciences

Department

Chemistry

First Advisor

Dr. John P. Selegue

Abstract

A variety of organometallic-fused heterocycles and acene quinones were prepared and characterized. This work was divided into three parts: first, the synthesis of 5,5-fused heterocyclic complexes of tricarbonylmanganese and (1’,2’,3’,4’,5’-pentamethylcyclopentadienyl)ruthenium; second, the synthesis of 1,2-diacylcyclopentadienyl p-cymene complexes of ruthenium(II); and third, synthesis of cyclopentadienyl-fused polyacenequinone complexes of ruthenium, iron and manganese.

The first examples of the convenient, versatile and symmetric cyclopentadienyl-fused heterocycle complexes of (1’,2’,3’,4’,5’-pentamethylcyclopentadienyl)ruthenium(II) and tricarbonylmanganese(I) were synthesized starting from (1,2-dicarbophenoxycyclopentadienyl)sodium. The sodium salt was transmetalated using [MnBr(CO)5] and 1/4 [Ru(μ3-Cl)(Cp*)]4 to give [Mn(CO)35-C5H3(CO2Ph)2-1,2}] and [Ru{η5-C5H3(CO2Ph)2-1,2}(Cp*)]. The diester complexes were saponified under basic conditions to obtain the corresponding dicarboxylic acids. The dicarboxylic acids were used to synthesize unique cyclopentadienylmetal complexes including diacyl chlorides, anhydrides, thioanhydrides and p-tolyl imides of ruthenium and manganese.

Similarly, a series of 1,2-diacylcyclopentadienyl-p-cymene cationic complexes of ruthenium were synthesized using thallium salt of 2-acyl-6-hydroxyfulvene and [Ru(η6-p-cymene)(μ-Cl)Cl]2 in a 2:1 ratio with an intension of converting them into heterocycle-fused cationic sandwich complexes. However, our attempts of ring closing on 1,4-diketons with sulfur or selenium were unsuccessful. A methodology involving the synthesis of metallocene-fused quinone complexes was employed starting from pentamethylruthenocene-1,2-dicarboxylic acids. The diacyl chloride was prepared in situ from the dicarboxylic acids and used for Friedel-Crafts acylation. We observed single-step room-temperature diacylation of aromatics, including benzene, o-xylene, toluene, 1,4-dimethoxybenzene and ferrocene with pentamethylruthenocene-1,2-diacyl chloride to obtain the corresponding quinone complexes. Similarly, we synthesized mononuclear and binuclear γ-quinones by aldol condensation of 1,2-diformylcyclopentadienylmetal complexes with cyclohexane-1,4-dione or 1,4-dihydroxyarenes.

The third methodology involves the Friedel-Crafts acylation of ferrocene with 2-carbomethoxyaroyl chlorides followed by saponification, carbonyl reduction, and ring closing by second Friedel-Crafts acylation to give Ferrocene-capped anthrone-like tricyclic and tetracyclic ketones. The oxidation of the ketones gave [3,4-c]-fused α-quinone complexes of iron. The oxidative and reductive coupling, enolization and C-alkylation of the anthrone complex were studied. Solvolysis of α-carbinol gave α-ferrocenylcarbenium salt, which underwent dimerization on treatment with non-nucleophilic base. We were successful to trap the in situ generated trimethylsilylenol ether of ferrocene-anthrone using dienophiles like N-phenylmaleimide or dimethylacetylenedicarboxylate under Diels-Alder conditions.

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Chemistry Commons

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