Braunschweig Holger, Herbst Thomas, Rais Daniela, Ghosh Sundargopal, Kupfer Thomas, Radacki Krzysztof, Crawford Andrew G, Ward Richard M, Marder Todd B, Fernández Israel, Frenking Gernot
Institut für Anorganische Chemie, Bayerische Julius-Maximilians-Universität Würzburg Am Hubland, 97 074 Würzburg, Germany.
J Am Chem Soc. 2009 Jul 1;131(25):8989-99. doi: 10.1021/ja902198z.
Room temperature photolysis of aminoborylene complexes, [(CO)(5)M=B=N(SiMe(3))(2)] (1: M = Cr, 2: Mo) in the presence of a series of alkynes and diynes, 1,2-bis(4-methoxyphenyl)ethyne, 1,2-bis(4-(trifluoromethyl)phenyl)ethyne, 1,4-diphenylbuta-1,3-diyne, 1,4-bis(4-methoxyphenyl)buta-1,3-diyne, 1,4-bis(trimethylsilylethynyl)benzene and 2,5-bis(4-N,N-dimethylaminophenylethynyl)thiophene led to the isolation of novel mono and bis-bis-(trimethylsilyl)aminoborirenes in high yields, that is [(RC=CR)(mu-BN(SiMe(3))(2)], (3: R = C(6)H(4)-4-OMe and 4: R = C(6)H(4)-4-CF(3)); [{(mu-BN(SiMe(3))(2)(RC=C-)}(2)], (5: R = C(6)H(5) and 6: R = C(6)H(4)-4-OMe); [1,4-bis-{(mu-BN(SiMe(3))(2)(SiMe(3)C=C)}benzene], 7 and [2,5-bis-{(mu-BN(SiMe(3))(2) ((C(6)H(4)NMe(2))C=C)}-thiophene], 8. All borirenes were isolated as light yellow, air and moisture sensitive solids. The new borirenes have been characterized in solution by (1)H, (11)B, (13)C NMR spectroscopy and elemental analysis and the structural types were unequivocally established by crystallographic analysis of compounds 6 and 7. DFT calculations were performed to evaluate the extent of pi-conjugation between the electrons of the carbon backbone and the empty p(z) orbital of the boron atom, and TD-DFT calculations were carried out to examine the nature of the electronic transitions.
在一系列炔烃和二炔烃（1,2 - 双（4 - 甲氧基苯基）乙炔、1,2 - 双（4 - （三氟甲基）苯基）乙炔、1,4 - 二苯基丁 - 1,3 - 二炔、1,4 - 双（4 - 甲氧基苯基）丁 - 1,3 - 二炔、1,4 - 双（三甲基甲硅烷基乙炔基）苯和2,5 - 双（4 - N，N - 二甲基氨基苯基乙炔基）噻吩）存在的情况下，对氨基硼烯配合物[(CO)(5)M = B = N(SiMe(3))(2)]（1：M = Cr，2：Mo）进行室温光解，可高产率分离得到新型单和双 - 双 - （三甲基甲硅烷基）硼杂环戊二烯，即[(RC = CR)(μ - BN(SiMe(3))(2)]（3：R = C(6)H(4) - 4 - OMe，4：R = C(6)H(4) - 4 - CF(3)）；[{(μ - BN(SiMe(3))(2)(RC = C - )}(2)]（5：R = C(6)H(5)，6：R = C(6)H(4) - 4 - OMe）；[1,4 - 双 - {(μ - BN(SiMe(3))(2)(SiMe(3)C = C)}苯]，7和[2,5 - 双 - {(μ - BN(SiMe(3))(2) ((C(6)H(4)NMe(2))C = C)} - 噻吩]，8。所有硼杂环戊二烯均以浅黄色、对空气和湿气敏感的固体形式分离得到。通过(1)H、(11)B、(13)C核磁共振光谱和元素分析对新的硼杂环戊二烯在溶液中进行了表征，并通过化合物6和7的晶体学分析明确确定了结构类型。进行密度泛函理论（DFT）计算以评估碳骨架电子与硼原子空p(z)轨道之间的π共轭程度，并进行含时密度泛函理论（TD - DFT）计算以研究电子跃迁的性质。
