Synthesis, Structural Analysis, and Functional Group Interconversion in the [ closo ‐B 10 H 8 ‐1,10‐X 2 ] 2 – (X = CN, [OCRNMe 2 ] + , OCOR, and [OH 2 ] + ) Derivatives

Derivatives [ closo ‐B 10 H 8 ‐1,10‐(CN) 2 ] 2– and [ closo ‐B 10 H 8 ‐1,10‐(OCHNMe 2 ) 2 ], efficiently obtained from [ closo ‐B 10 H 8 ‐1,10‐(IPh) 2 ] by nucleophilic substitution with CN – and DMF, were envisioned as precursors to diacid [ closo ‐B 10 H 8 ‐1,10‐(COOH) 2 ] 2– and to dihydroxy derivative [ closo ‐B 10 H 8 ‐1,10‐(OH) 2 ] 2– , respectively. Attempts at hydrolysis or reduction of the dinitrile gave no reaction or complex mixtures of products. In contrast, the DMF adduct was cleanly hydrolyzed to diformate [ closo ‐B 10 H 8 ‐1,10‐(OCHO) 2 ] 2– and subsequently to protonated dihydroxy [ closo ‐B 10 H 8 ‐1,10‐(OH 2 ) 2 ]. The latter was O‐acylated with PhCOCl. Crystal and molecular structures of five derivatives were established by single crystal XRD methods and compared to those for other [ closo ‐B 10 H 8 ‐1,10‐X 2 ] 2– derivatives. Trends in molecular geometry in the series and also reactivity of the dinitrile and intermediates were corroborated and correlated with DFT results (B3LYP/TZVP) by analysis of bonding, charge distribution and vibrational frequencies.