Procedure for the degradation of 1,2-(PR2)2-1,2-dicarba-closo-dodecaborane(12) and 1-(PR2)-2-R′-1,2-dicarba-closo-dodecaborane(12)

Teixidor, Francesç; Viñas, Clara; Abad, Mónica Viñarás; Núñez, Rosario; Kivekäs, Raikko; Sillanpää, Reijo

doi:10.1016/0022-328x(95)05558-7

Cited by 77 publications

(62 citation statements)

References 34 publications

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“…The structures are similar, diverging from one another in the six-membered ring at the phosphorus atoms: a planar phenyl ring in 3 and cyclohexyl rings with normal chair conformation in 5 (see bond parameters in Table 2). Slight differences in the P À C bonds originate from the aromatic and aliphatic carbon [53] are to high frequency. 10 33.82 [54] 1-OPiPr 2 -2-Me-1,2-closo-C 2 B 10 H 10 (4) 58.18 + 24.36 1-PPh 2 -2-Ph-1,2-closo-C 2 B 10 H 10 12.66 [56] 1-OPPh 2 -2-Ph-1,2-closo-C 2 B 10 H 10 (6) 19.65 + 6.99 1-SePPh 2 -2-Ph-1,2-closo-C 2 B 10 H 10 (18) 45.06 + 32.16 1-PiPr 2 -2-Ph-1,2-closo-C 2 B 10 H 10 38.50 [57] 1-OPiPr 2 -2-Ph-1,2-closo-C 2 B 10 H 10 (7) 53.27 + 14.77 1-PiPr 2 -1,2-closo-C 2 B 10 H 11 54.20 [18] 1-SPiPr 2 -1,2-closo-C 2 B 10 H 11 (13) 77.90 + 23.74 1-SePiPr 2 -1,2-closo-C 2 B 10 H 11 (16) 83.67 The structural analysis of 9 confirmed that only one of the two phosphorus atoms bonded to the closo cage was oxidized by sulfur (Figure 4and Table 3).…”

Section: Resultsmentioning

confidence: 99%

Uncommon Coordination Behaviour of P(S) and P(Se) Units when Bonded to Carboranyl Clusters: Experimental and Computational Studies on the Oxidation of Carboranyl Phosphine Ligands

Popescu

Laromaine

Teixidor

et al. 2011

Chemistry A European J

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Oxidation of closo-carboranyl diphosphines 1,2-(PR(2))(2)-1,2-closo-C(2)B(10)H(10) (R=Ph, iPr) and closo-carboranyl monophosphines 1-PR(2)-2-R'-1,2-closo-C(2)B(10)H(10) (R=Ph, iPr, Cy; R'=Me, Ph) with hydrogen peroxide, sulfur and elemental black selenium evidences the unique capacity of the closo-carborane cluster to produce uncommon or unprecedented P/P(E) (E=S, Se) and P=O/P=S chelating ligands. When H(2)O(2) reacts with 1,2-(PR(2))(2)-1,2-closo-C(2)B(10)H(10) (R=Ph, iPr), they are oxidized to 1,2-(OPR(2))(2)-1,2-closo-C(2)B(10)H(10) (R=Ph, iPr). However, when S and Se are used, different reactivity is found for 1,2-(PPh(2))(2)-1,2-closo-C(2)B(10)H(10) and 1,2-(PiPr(2))(2)-1,2-closo-C(2)B(10)H(10). The reaction with sulfur produces mono- and dioxidation products for R=Ph, whereas Se produces the mono-oxidation product only. For R=iPr, only monooxidation takes place with S, and the second C(c)-PiPr(2) bond breaks to yield 1-SPiPr(2)-1,2-closo-C(2)B(10)H(11). When Se is used, only 1-SePiPr(2)-1,2-closo-C(2)B(10)H(11) is formed. The potential of the mono-chalcogenide carboranyl diphosphines 1-EPPh(2)-2-PPh(2)-1,2-closo-C(2)B(10)H(10) (E=S, 9; Se, 15) to behave as unsymmetric chelating bidentate ligands was studied for different metal complexes, different solvents and in the solid state. Dechalcogenation takes place in each case. Computational studies provided information on the P=E (E=S, Se) bonds. Steric effects block the bonding ability of the P=E group due to interactions between the chalcogen and the neighbouring hydrogen atoms (three from the phenyl rings and one from the carborane cluster). The electronic effects originate from the strongly electron-withdrawing character of the closo carborane cluster, which polarizes the P=E (E=S, Se) bond towards the phosphorus atom. As a consequence, the E atom is the electron-poor site and the P atom the electron-rich site in the P=E bond.

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Section: Resultsmentioning

confidence: 99%

Uncommon Coordination Behaviour of P(S) and P(Se) Units when Bonded to Carboranyl Clusters: Experimental and Computational Studies on the Oxidation of Carboranyl Phosphine Ligands

Popescu

Laromaine

Teixidor

et al. 2011

Chemistry A European J

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“…Figure 2. Molecular structures of (R P ,R P )-(top) and (R P ,S P )-1,2-bis[adamantyloxy-(-)-menthyloxyphosphanyl]-closo-dicarbaborane(12) (bottom) (6) with thermal ellipsoids at 50 % probability level. H atoms and solvent molecules have been omitted for clarity.…”

Section: Preparation and Molecular Structures Of Phosphanylcarbaboranmentioning

confidence: 99%

“…[5] Use of phosphanyl ligands provides a simple method for controlling steric and electronic properties through structural manipulation. The only non-chiral phosphanylcarbaborane(12), 1,2-bis(diethoxyphosphanyl)-closo-dicarbaborane (12), obtained starting from commercially available diethyl chlorophosphite, was reported in 1994, [6] however, no structurally characterised phosphanylcarbaborane(12) compounds have since been described.…”

Section: Introductionmentioning

confidence: 99%

Enantiomerically Pure Bis(phosphanyl)carbaborane(12) Compounds

et al. 2009

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Enantiomerically pure (R P ,R P )-and (R P ,S P )-1,2-bis[1-adamantyloxy-(-)-menthyloxyphosphanyl]-closo-dicarbaborane(12), 1,2-bis[bis(-)-menthyloxyphosphanyl]-closo-dicarbaborane(12) and 1,2-bis[bis(4-tert-butylphenyloxy)phosphanyl]-closo-dicarbaborane(12) were synthesised by the reaction of dilithiated 1,2-dicarba-closo-dodecaborane(12) with two equivalents of the corresponding chlorophosphite. The phosphonites are stable towards epimerisation, oxygen and water. P···P through-space coupling was observed, and the 3 J PP cou-

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“…The reaction of the NHC 1,3-dimethylimidazol-2-ylidene (2) with ortho-carborane (1) in a 3:1 ratio was carried out in dry THF (Scheme 2). [10] A carborane/base ratio of 1:2 or lower [3][4][5][6][7][8]11] is typically used for the deboronation of orthocarborane. After two hours at ambient temperature, the solvents were removed in vacuo and isopropanol was added.…”

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confidence: 99%