Unusual Cationic Tris(Dimethylsulfide)-Substituted closo-Boranes: Preparation and Characterization of [1,7,9-(Me₂S)₃-B₁₂H₉] BF₄ and [1,2,10-(Me₂S)₃-B₁₀H₇] BF₄

Abstract

Rational syntheses of trisubstituted sulfur-bearing closo-boranes are presented. In the development of these syntheses unusual cationic closo-boranes [1,7,9-(Me(2)S)(3)-B(12)H(9)](+) (3) and [1,2,10-(Me(2)S)(3)-B(10)H(7)](+) (4) have been identified. These were initially recognized to be intermediates in the formation of the neutral trisubstituted species 1,7-(Me(2)S)(2)-9-(MeS)-B(12)H(9) (1) and 1,10-(Me(2)S)(2)-2-(MeS)-B(10)H(7) (2), respectively. Stable tetrafluoroborate salts were prepared and isolated, and their structures are presented. They are believed to represent the first structural determinations of cationic borane clusters of any type.

Dimethyloxonium and Methoxy Derivatives of nido-Carborane and Metal Complexes Thereof

“…In the 1 H NMR spectra of K [3] and K [4] the signals of methoxy groups are shifted to high field in comparison with 1 and 2 up to 3.22 and 3.17 ppm, respectively, and appear as 1:1:1:1 quartets due to long-range B-H coupling ( 3 J B,H = 3.7-3.8 Hz). Such coupling has also been previously observed for some organoboron compounds [29][30][31][32], methylsulfanyl derivatives of the closo-dodecaborate anion [33,34] and B-methysulfanyl derivatives of cobalt bis(dicarbollide) anion [35].…”

Unusual cationic rhodathiaboranes: synthesis and characterization of [8,8,8-(H)(PR3)2-9-(Py)-nido-8,7-RhSB9H10]+and [1,3-μ-(H)-1,1-(PR3)2-3-(Py)-isonido-1,2-RhSB9H8]+

“…Since the yields of these neutral 11-vertex rhodathiaboranes are generally good, this is a convenient entry into the area of polyhedral boron-containing cations which is scarcely explored with only a small number of reported cationic boranes and metallaheteroboranes. [39][40][41][42][43][44][45][46][57][58][59][60][61][62][63] It is important to recall that the majority of reported cationic metallaheteroboranes generally contain charge-compensating ligands; [41][42][43][44][45][46] and the number of cationic polyhedral boron clusters formed by simple protonation is very small indeed. 39,40 The herein reported reactions with TfOH together with previous results with HCl 36,64 give an overall view of the reactivity of this family of rhodathiaboranes with Brønsted acid (Scheme 4).…”

Access to cationic polyhedral carboranes via dynamic cage surgery with N-heterocyclic carbenes

“…On the contrary, o-2 and m-2 were unexpectedly converted into their corresponding hydrochlorides o-2a and m-2a, which is, to the best of our knowledge, the first example of a proton capture by a neutral borane cage leading to the formation of a cation without any changes in the functional groups. Such a reactivity is known for of amino, sulfido or phosphino based exoskeletal functional groups protonation or quaternization [30][31][32] . In this respect, there is only one example of the substitution of sulfide groups in bis-dialkylsulfidododecahydrodecaborane with hydrogen halogenides 45 .…”