Title

New synthetic approaches to triosmium decacarbonyl bisethoxide and the systematic design of linked triosmium clusters via bridging diols.

Date of Award

5-1-2016

Document Type

Thesis

School

College of Liberal Arts

Degree Name

Bachelor in Arts

Abstract

With the goal of developing systematic syntheses of linked triosmium carbonyl clusters, we report the substitution reactions of the dibridged cluster Os-b3-s(CO)10(µ-p2-s-OEt)-p2-s with the bifunctional ligand 1,5-pentanediol. Reaction of Os-b3-s(CO)-b10-s(µ-p2-s-OEt)-b2-s with 1,5-pentanediol affords the cluster Os-b3-s(CO)-b10-s(µ-p2-sO(CH-b2-s)-b5-sOH)-b2-s as the major product. Over extended reaction periods, quantitative conversion to the cluster H-b4-sOs-b4-s(CO)-b12-s is observed. Linking of two triosmium carbonyl clusters via the 1,5-pentanediol bridging ligands has been achieved in the reaction of Os-b3-s(CO)-b10-s(µ-p2-s-O(CH-b2-s)-b5-sOH)-b2-s with one molar equivalent of Os-b3-s(CO)-b10-s(µ-p2-s-OEt)-b2-s. A secondary product of this reaction has been characterized spectroscopically and is believed to be an intermediate in the formation of H-b4-sOs-b4-s(CO)-b12-s. A synthetic route to Os-b3-s(CO)-b10-s(µ-p2-s-OEt)-b2-s via di-halogenated cluster intermediate Os-b3-s(CO)-b12-sX-b2-s or Os-b3-s(CO)-b10-s(µ-p2-s-X)-b2-s (X = Cl, Br, I) is also reported.