1‐Alkyl‐2,5‐(ortho‐phenylene)‐1‐carbapenta‐borane(10)

Hexaethyl‐2,3,5‐tricarba‐nido‐hexaborane(7), Its Monoanion and the (Triphenylphosphane)gold and Dicarbonylrhodium Complexes

“…The assignment of NMR signals was done in the usual way by 1D and 2D methods. [15] The typically broad 13 C NMR signals of carbon atoms linked to boron atoms [16] are easy to recognize and can be distinguished by selective heteronuclear decoupling experiments 13 C, based on optimized gas-phase structures, confirms the previous suggestion for 1 [18] (R = H, Me) that the carbon atom C2, which bears the endo hydrogen atom, belongs to the cluster. The optimized structure of 1 with R = Et shows slight variations of the bond lengths between B1 and atoms in the base.…”

“…[5] Scheme 1b shows that the condensations can be modified to integrate a C 2 unit into the arachno-carbaborane 4. [13] This is short-lived and rearranges fast into 2. [7] Both 1 and 2 react with Na[Et 3 BH] in hexane by deprotonation to give the anions 1 -[5] and 2 - [7] respectively.…”

“…NMR parameters were calculated [32,33] at the same level of theory. Calculated chemical shifts δ 13 C and δ 11 B were converted by δ 13 C(calcd.) = σ( 14 mmol) was added.…”

2,3,4-Tricarba-nido-hexaboranes(7) with a Bridging B−Ethyl−B Moiety

“…[7] The C 2 -bridged arachno-carborane 9 is comparable with a benzo derivative that has already been characterized. [9] The intermediacy of 9 (prior to elimination of EtBH 2…”

Quenched gas-phase reactions of tetraborane(10), B4H10, with substituted alkynes: new nido-dicarbapentaboranes and arachno-monocarbapentaboranes

“…21 Many arachno-monocarbapentaboranes of the type 1-CB 4 H 10 with a bridge between B2 and B5 have since been reported. [30][31][32][33] It is notable that the formation of 4a involves cleavage of the triple bond present in the propyne, whereas this bond remains intact in the formation of 1a, 2a and 3a. A minor isomer was often observed in the fraction of 4a and was identified as 2,5-l-endo-MeCH-1-CB 4 H 8 5a on the basis of ab initio computations carried out elsewhere.…”