Structure of 3-(η2,η2-1,5-cyclooctadiene)-3-pallada-1,2-dicarba-closo-dodecaborane(11)

Large-cage (11–13-vertex) dicarbon metallacarboranes of platinum metals with mono- and polycyclic diolefin ligands

“…The analogous palladacarborane [3,3-( 4 -C 8 H 12 )-1-R-2-R 1 -3,1,2-closo-PdC 2 B 9 H 9 ] (6a, R = R 1 = H) was synthesized in 70% yield by the diamine-COD ligand displacement reaction of [3,3-{(CH 3 ) 2 N(CH 2 ) 2 N(CH 3 ) 2 }-3,1,2-closo-PdC 2 B 9 H 11 ] (7) with an excess of COD in the presence of gaseous HCl in CH 2 Cl 2 (it was reported that the reaction does not proceed under neutral conditions) [4]. Complex 6a was also generated, along with other unidentified products, in the reaction of Tl 2 [7,8-nido-C 2 B 9 H 11 ] (8) [5] with the cationic complex [( 4 -C 8 H 12 )Pd( 5 -C 5 H 5 )][BF 4 ] [6]. The results of a comparative crystallographic study of complexes 6a [6] and 7 [4] showed that the asymmetry in the bonding of the metal atom to the C 2 B 9 cage ('slipping' distortion of the {PdC 2 B 9 } framework) in 7 (Pd· · ·B(4, 7), 2.182Å; Pd· · ·B(8), 2.205Å; Pd· · ·C(1, 2), 2.623 and 2.608Å) is substantially smaller than that observed in complex 6a (Pd· · ·B(4, 7, 8), 2.178-2.294Å; Pd· · ·C(1, 2), 2.377 and 2.432Å).…”

“…Synthesis of exo-closo-bimetallacarborane clusters 53a and b [25]. 6 ] was found to produce the dinuclear complexes [RhW(-CC 6 H 4 Me-4)(CO) 2 (PPh 3 ) 2 ( 5 -C 2 B 9 H 8 (C 7 H 9 )R 2 )] (54a, R = H (two isomers); b, R = Me), in which the NBD ligand was unexpectedly inserted into a B-H bond of the C 2 B 9 -cage ligand accompanied by the C-C bond formation to give the nortricyclene moiety (Scheme 19) [45].…”

“…Proposed synthesis of dimer 92 via binuclear reductive elimination mechanism [69]. 6 ] with the mono-Tl + salt of the [7-CH 3 -9-Ph-7,9-nido-C 2 B 9 H 10 ] − anion in toluene at room temperature. The structure of complex 89 was assigned based on the IR and 1 H NMR spectroscopic data, by comparison with those of 3 -cyclooctenyl-type rhodium complexes, which have been prepared earlier by protonation of anions 18a-c with CF 3 COOH [13].…”

“…Complex 6a was also generated, along with other unidentified products, in the reaction of Tl 2 [7,8-nido-C 2 B 9 H 11 ] (8) [5] with the cationic complex [( 4 -C 8 H 12 )Pd( 5 -C 5 H 5 )][BF 4 ] [6]. The results of a comparative crystallographic study of complexes 6a [6] and 7 [4] showed that the asymmetry in the bonding of the metal atom to the C 2 B 9 cage ('slipping' distortion of the {PdC 2 B 9 } framework) in 7 (Pd· · ·B(4, 7), 2.182Å; Pd· · ·B(8), 2.205Å; Pd· · ·C(1, 2), 2.623 and 2.608Å) is substantially smaller than that observed in complex 6a (Pd· · ·B(4, 7, 8), 2.178-2.294Å; Pd· · ·C(1, 2), 2.377 and 2.432Å). This fact has been attributed to the difference in the -acid character of the exopolyhedral ligands in these complexes [6].…”

“…This fact reflects the partial double-bond character of the C 4 -ring bonds coordinated to the metal atom. The reactions of 2 with the electrophilic reagents [AuCl(PPh 3 )] and [Co(CO) 2 (NCCH 3 )( 4 -C 4 Me 4 )][PF 6 ] were studied. These reactions produced the zwitterionic complexes [3,3-{ 4 -(tBu 2 C 2 P 2 M )}-3,1,2-closo-RhC 2 B 9 H 11 ] (3a, M = AuPPh 3 ; b, M = Co(CO) 2 ( 4 -C 4 Me 4 )), respectively, wherein the incoming metal groups are coordinated by the phosphorus atom of the { 4 -(t-Bu 2 C 2 P 2 )} ring.…”