STRUCTURES OF, AND CHARGE SEPARATION IN, "2,3-DIPHENYL-4,4-DICYANOTRIAFULVENE AND 2,3-DIPHENYLCYCLOPROPENONE
STRUCTURES OF, AND CHARGE SEPARATION IN, "2,3-DIPHENYL-4,4-DICYANOTRIAFULVENE AND 2,3-DIPHENYLCYCLOPROPENONE
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DOI：
10.1021/ja00802a033
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发表时间：
1973-01-01
影响因子：
15
通讯作者：
AMMON, HL
中科院分区：
文献类型：
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作者：
AMMON, HL
用MoK-X-射线衍射法测定了2，3-二苯基-4，4-二氰基三富烯(氰基)和2，3-二苯基环丙酮(PROPEN)的晶体结构。晶胞参数为a=106.546，b=20.658，c=25.081，Z=16，晶胞参数分别为a=9.5800，b=10.0791，c=14.2918？，？=106.546，Z=4；晶胞参数为a=9.291，b=20.658，c=25.081，Z=16。利用该数据对四个最小二乘函数进行了检验。通过CNDO/2计算得到了电荷密度和键序信息。环丙烯中的电荷量比饱和酮中相应的电荷量大0.12-0.14e。PROPEN中O(-0.387)上的负电荷比氰基(-0.366)中的C(CN)2上的大，但其余分子中的正电荷分布使更多的电荷分布在氰基苯基上。这一结果与2，3-二(对氟苯基)-4，4-二氰基三富烯和2，3-二(对氟苯基)环丙烯的相对~(19)F核磁共振化学位移是一致的，富烯是非交替的碳氢化合物，通过a电子对朝向或远离不饱和环的移动而形式上达到Hück l芳香族状态。介孔结构，如二电子环丙烯形式的三氟烯(L)1和六电子环戊二烯形式
The crystal structures of 2, 3-diphenyl-4, 4-dicyanotriafulvene (CYANOF) and 2, 3-diphenylcyclopro-penone (PROPEN) have been determined with Mo K X-ray diffraction data. CYANOF= crystallizes in the mono-clinic space group Alfa, with cell parameters of a= 9.5800, b= 10.0791, c= 14.2918 Á, and ß= 106.546 and Z= 4. PROPEN crystallizes as the monohydratein the orthorhombic space group Pbca with cell parameters of a= 9.291, b= 20.658, and c= 25.081 Á and Z= 16. The final R factors were 0.035 for CYANOF and 0.043 for PROPEN after full-matrix least-squares structure refinement. Four least-squares minimization functions were tested with the CYANOF data. CNDO/2 calculations have been carried out to obtain charge density and bond order information. TheO charge magnitudes in cyclopropenones are 0.12-0.14 e larger than the corresponding charges in saturated ketones. There is a larger negative charge on O in PROPEN (—0.387) than on the C (CN) 2 group in CYANOF (—0.366), but the positive charge distributions in the remainder of the molecules place more of the charge on the CYANOF phenyl than on the PROPEN phenyl. This result is in accord with the relative 19F nmr chemical shifts of 2, 3-di (p-fluorophenyl)-4, 4-dicyanotriafulvene and 2, 3-di (p-fluorophenyl) cyclopropenone.The fulvenes are nonalternant hydrocarbons which can formally reach Hückel aromatic status by the shift of a-electron paireither toward, or away from, an unsaturated ring. Mesomeric structuressuch as the two-electron cyclopropenium form of triafulvene (l) 1 and the six-electron cyclopentadienide form of