. . "P(LN00A028), Z(AV0Z4032918)" . "\u0160t\u00EDbr, Bohumil" . . "6" . "783;790" . "67" . "RIV/61388980:_____/02:50023002" . "Holub, Josef" . . . "3"^^ . . "8"^^ . "Some halogenation reactions of nido-7,8,9,11-P2C2B7H9." . "Some halogenation reactions of nido-7,8,9,11-P2C2B7H9." . . "3"^^ . "0"^^ . "0"^^ . . . . . "boron; boranes; diphosphadicarbaboranes"@en . "Some halogenation reactions of nido-7,8,9,11-P2C2B7H9."@en . . . . "Some halogenation reactions of nido-7,8,9,11-P2C2B7H9."@en . . "RIV/61388980:_____/02:50023002!RIV/2003/AV0/A50003/N" . "Halogenations of the diphosphadicarbaborane nido-7,8,9,11-P2C2B7H9 using the AlCl3/CCl4, and I-2/AlCl3/C6H6 halogenation systems resulted in the formation of a mixture of mono- and disubstituted derivatives 10-X-nido-7,8,9,11-P2C2B7H8 (for X = Cl and I, yields 6 and 21%, respectively) and 5,10-X-2-nido-7,8,9,11-P2C2B7H7 (for X = Cl and I, yields 57 and 46%, respectively). These results show that the halogenation under electrophilic conditions takes place at positions most distant from the P atoms, but at sites adjacent to the CH units. In contrast, the bromination with N-bromosuccinimide in CH2Cl2 is probably of radical character, proceeding in positions adjacent to the P centres to give 3-Br-nido-7,8,9,11-P2C2B7H8 (yield 41%) and 2,3-Br-2-nido-7,8,9,11-P2C2B7H7 (yield 5%). The mixtures of the halo derivatives were separated by column chromatography on silica gel. Individual compounds were characterized by mass spectrometry and multinuclear (B-11, H-1, and P-31) spectroscopy combined with two-dimensio" . . . "Collection of Czechoslovak Chemical Communications" . "Bakardjiev, Mario" . "CZ - \u010Cesk\u00E1 republika" . "664204" . . "0010-0765" . . "Halogenations of the diphosphadicarbaborane nido-7,8,9,11-P2C2B7H9 using the AlCl3/CCl4, and I-2/AlCl3/C6H6 halogenation systems resulted in the formation of a mixture of mono- and disubstituted derivatives 10-X-nido-7,8,9,11-P2C2B7H8 (for X = Cl and I, yields 6 and 21%, respectively) and 5,10-X-2-nido-7,8,9,11-P2C2B7H7 (for X = Cl and I, yields 57 and 46%, respectively). These results show that the halogenation under electrophilic conditions takes place at positions most distant from the P atoms, but at sites adjacent to the CH units. In contrast, the bromination with N-bromosuccinimide in CH2Cl2 is probably of radical character, proceeding in positions adjacent to the P centres to give 3-Br-nido-7,8,9,11-P2C2B7H8 (yield 41%) and 2,3-Br-2-nido-7,8,9,11-P2C2B7H7 (yield 5%). The mixtures of the halo derivatives were separated by column chromatography on silica gel. Individual compounds were characterized by mass spectrometry and multinuclear (B-11, H-1, and P-31) spectroscopy combined with two-dimensio"@en . "[0E0E31D96233]" .