mahmoud aljoumhawy

• The content of this Ph.D. thesis is divided into two main topics. The first chapter presents a novel synthesis of dodecahydro-closo-dodecaborate anion [B12H12]2- derivatives. Nowadays, boron-rich dodecahydro-closo-dodecaborate anion [B12H12]2- has gained wide interest and providing great opportunities in designing of various geometric and electronic structures with promising properties useful for modern host-guest chemistry and organoelement chemistry, in addition to its wide application in medicinal chemistry. Herein, we report our efforts on the development of a novel synthesis of cyclic oxonium derivatives of [B12H12]2-and effective approach to mono-halogenation [B12H11X]2- (X= I, Br, Cl) of dodecahydro-closo dodecaborate anion, the procedure yields therefore much purer material than any of the literature procedures, the yields are very high, and work-up is very straight-forward. Additionally, an attractive methodology for construction of B-N bond has been established. In general, derivatization of the dodecahydro-closo-dodecaborate dianion [B12H12]2- suffers from the lack of efficient methodology for introducing N-containing organic moieties to boron cage, thus, we have developed an approach based on the palladium-catalyzed cross-coupling amination of [B12H11I]2- . The new methodology provides broad scope of B12-N-containing organic moieties in good to excellent yield. The second chapter highlights the synthesis and application of heptamethine cyanine green dyes. In details, synthesis of heptamethine indocyanine green dyes by addressing different positions in the chemical structure of the cyanine dye skeleton with the aim to generate green dye with optimal aqueous solubility and fewer tendencies to form aggregation. The staining ability of dye, toxicity, and stability in aqueous solution have been investigated. Two of the new substances stained the model for inner limiting membrane (ILM) in green and showed good stability in aqueous solution.