Cationic Dialkyl Metal Compounds of Group 13 Elements (E = Al, Ga, In) Stabilized by the Weakly Coordinating Dianion [B₁₂Cl₁₂]^2–

Synthesis, structure, and reactivity of AlMe2(1-Me-CB11F11): An AlMe2+ cation-like species bonded to a superweak anion

“…The primary Al-F bonds are rather long, which is one of the reasons that the C-Al-C angle, at 147.6(2)8, is quite large. Compare the CAl-C angles in Knapp's compound, (AlMe 2 ) 2 B 12 Cl 12 , which is 133.8(4)8 [2]). However, another reason that the angle is so large is that there are two weak AlÁ Á ÁF interactions (together they account for only 3.8% of the sum of bond valences for Al; see below).…”

“…The two graphs in Fig. 4 show the tendency of the Al-CH 3 bonds to lengthen as the Al-F bonds shorten (from [AlMe 2 (1-Me-CB 11 F 11 )] 2 to [AlMe 2 F] 4 to [N(n-Bu) 4 ][AlMe 2 F 2 ], bottom graph) and the tendency of the H 3 C-Al-CH 3 angle to decrease as the F-Al-F angle increases Table 2 [2,10]). This suggests that the Al atoms in [AlMe 2 (1-Me-CB 11 F 11 )] 2 are more reactive (i.e., have a greater degree of positive charge, hence the ''cation-like'' designation) than the Al atoms in the AlMe 2 F 2 À anion.…”

“…Cationic aluminum complexes are of considerable interest due to their potential use in a variety of organic and catalytic transformations [1][2][3][4][5][6][7]. The most reactive are undoubtedly the cation-like species AlR 2 + bonded to carborane and borane superweak anions, which have been isolated and characterized by Reed and co-workers (AlEt 2 (CB 11 H 6 Cl 6 ) and AlEt 2 (CB 11 H 6 Br 6 )) [7] and by Knapp and co-workers ((AlMe 2 ) 2 (B 12 Cl 12 ) and (AlEt 2 ) 2 (B 12 Cl 12 )) [2].…”

“…The most reactive are undoubtedly the cation-like species AlR 2 + bonded to carborane and borane superweak anions, which have been isolated and characterized by Reed and co-workers (AlEt 2 (CB 11 H 6 Cl 6 ) and AlEt 2 (CB 11 H 6 Br 6 )) [7] and by Knapp and co-workers ((AlMe 2 ) 2 (B 12 Cl 12 ) and (AlEt 2 ) 2 (B 12 Cl 12 )) [2]. We herein report the synthesis, structure, and reactivity of another such species, AlMe 2 (1-Me-CB 11 F 11 ).…”

Synthesis and Applications of Perfunctionalized Boron Clusters

“…103 The same group later disclosed the stabilization of [Al(CH 3 ) 2 ] + using this dodecaborate anion. 104 It should be noted that Wehmschulte and co-workers reported a similar complexes employing a perfunctionalized dodecaborate as a counterion, including [Ag(CH 3 CN)][B 12 Cl 11 (NMe 3 )], [CPh 3 ][B 12 Cl 11 (NMe 3 )], and [Et 2 Al][B 12 Cl 11 (NMe 3 )]. 105 …”