Oligo(cyclohexylidenes): Parent Compounds and End-Functionalized Derivatives
摘要:
Parent oligo(cyclohexylidenes) 1(n) (n = 1-4) were synthesized using a modified Barton-Kellogg olefin synthesis. Surprisingly, the crude compounds 1(2) and 1(4) contained small amounts of the 1(n-1) and 1(n+1) homologues. As evidenced by a close examination of mass spectral data of selectively deuterated tercyclohexylidenes 1(2)d(4)d(4) and 1(2)-d(8), their formation can be attributed to scrambling of the intermediate azines. With increasing n, a marked decrease in solubility as well as an increase in thermal stability was found. Powder diffraction measurements indicate that the parent compounds 1(n), irrespective of n, pack in a similar fashion in the solid state. The theoretically (MMX, AM1, and ab initio) predicted rodlike structure of the oligo(cyclohexylidenes) was confirmed by single-crystal X-ray structures of 1(1) and three derivatives (12(1), 13(1), and 30(2)). In line with the powder diffraction data in the series 1(n), a similar packing motif was found for the derivatives. To circumvent side product formation due to azine scrambling, a different synthetic approach was used for the preparation of end-functionalized oligo(cyclohexylidenes), i.e. decarboxylation and dehydration of beta-hydroxy acids.
Oligo(cyclohexylidenes): Parent Compounds and End-Functionalized Derivatives
摘要:
Parent oligo(cyclohexylidenes) 1(n) (n = 1-4) were synthesized using a modified Barton-Kellogg olefin synthesis. Surprisingly, the crude compounds 1(2) and 1(4) contained small amounts of the 1(n-1) and 1(n+1) homologues. As evidenced by a close examination of mass spectral data of selectively deuterated tercyclohexylidenes 1(2)d(4)d(4) and 1(2)-d(8), their formation can be attributed to scrambling of the intermediate azines. With increasing n, a marked decrease in solubility as well as an increase in thermal stability was found. Powder diffraction measurements indicate that the parent compounds 1(n), irrespective of n, pack in a similar fashion in the solid state. The theoretically (MMX, AM1, and ab initio) predicted rodlike structure of the oligo(cyclohexylidenes) was confirmed by single-crystal X-ray structures of 1(1) and three derivatives (12(1), 13(1), and 30(2)). In line with the powder diffraction data in the series 1(n), a similar packing motif was found for the derivatives. To circumvent side product formation due to azine scrambling, a different synthetic approach was used for the preparation of end-functionalized oligo(cyclohexylidenes), i.e. decarboxylation and dehydration of beta-hydroxy acids.
between the functional groups and the hydrocarbon skeleton in a series of end-functionalized oligo(cyclohexylidenes) 1−12, their HeI photoelectron (PE) spectra were measured and analyzed. Vertical ionization energies, Ivj, of the highest occupied molecular orbitals (MOs) of 1−12 were assigned using ab initio RHF/6−31G* MO energies (−εj) in combination with Koopmans’ theorem. Excellent to good agreement was
为了确定在一系列末端官能化的低聚(亚环己基)1-12 中的官能团和烃骨架之间是否发生通过键(TB)轨道相互作用,测量并分析了它们的 HeI 光电子(PE)光谱。使用 ab initio RHF/6-31G* MO 能量 (-εj) 结合 Koopmans 定理分配了 1-12 的最高占据分子轨道 (MO) 的垂直电离能 Ivj。在 PES 和 RHF/6-31G* 结果之间发现了极好的一致性。此外,Ivj,作业进一步证实了-
Oligo(cyclohexylidene) oximes and derivatives as probe molecules for long-range substituent effects on 13C NMR chemical shifts
作者:Frans J. Hoogesteger、David M. Grove、Leonardus W. Jenneskens、Theodorus J. M. de Bruin、Bart A. J. Jansen
DOI:10.1039/p29960002327
日期:——
aliphatic oximes (1–4) the influence of the oximesubstituent on the 13C NMR chemical shifts has been studied. Various 2D NMR techniques were applied for the unequivocal assignment of their 1H and 13C resonances. For bicyclohexylidene oximes 1–2 long-range substituenteffects on the 13C NMR chemical shifts of aliphatic carbon atoms of the six-membered rings due to the presence of the oxime group are
对于一系列棒状脂肪族肟(1-4),已经研究了肟取代基对13 C NMR化学位移的影响。将各种2D NMR技术应用于其1 H和13 C共振的明确分配。对于双环己基肟,由于存在肟基,在六元环的脂肪族碳原子的13 C NMR化学位移上有1–2个远程取代基作用,直至远离亚氨基的6个碳碳键为止碳!在13从双环己基肟3-4获得的C NMR数据表明,在该系列反应中,作用仅限于与亚胺基碳有5个键的碳原子。观察到的两个系列之间的差异归因于存在于1-2中的烯烃双键,该双键被肟取代基的电场极化。
Aldehydic ketones and their use in perfumes
申请人:QUEST INTERNATIONAL B.V.
公开号:EP0967195A1
公开(公告)日:1999-12-29
The novel ketones having the structure
in which R is H or an alkyl group and X is a hydrocarbon group having between 4 and 12 carbon atoms, the ring being saturated or unsaturated, excluding 4-(1-ethylpropylidene)-1-cyclohexanone, 4-cyclohexylidene- 1-cyclohexanone,4-butylidene-1-cyclohex-2-enone, 4-(1-ethylpropylidene)-1-cyclohex-2-enone, 4-(2-methylpropylidene)-1-cyclohexanone,4-cyclohexyliden-2-cyclohexen-1-one, 4-(1,5-dimethyl-4-hexenylidene)-1-cyclohexanone, 4-[4-(cyclohexyliden)cyclohexyliden]-1-cyclohexanone, 4-[4-(tert-butyl)cyclohexyliden]-1-cyclohexanone, 4-[4-(cyclohexyl)cyclohexyliden]-1-cyclohexanone, 4-(2-isopropyl-5-methylcyclohexyliden)-2-cyclohexen-1-one and 4-(3-phenylpropylidene)-1-cyclohex-2-enone exhibit interesting odour characteristics, generally aldehydic in nature, and so find use in perfumes and in perfumed products.
(57) [摘要](有修改),(修改),(解决方法) ] 提供新的酮类化合物,这些酮类化合物表现出感兴趣的气味特征,一般呈醛状,可用于香水和芳香化产品。\具有以下结构Јn 的酮(其中 R 为 H 或烷基,X 为具有 4 至 12 个碳原子的烃基,环为饱和或不饱和环)
Photoinduced Intramolecular Charge Separation in Donor/Acceptor-Substituted Bicyclohexylidene and Bicyclohexyl
作者:Frans J. Hoogesteger、Cornelis A. van Walree、Leonardus W. Jenneskens、Martin R. Roest、Jan W. Verhoeven、Wouter Schuddeboom、Jacob J. Piet、John M. Warman
The photophysical properties of a bicyclohexylidene (1DA) and a bicyclohexyl (2DA) substituted with an anilino electron donor and a dicyanoethylene electron acceptor have been studied. Quenching of local donor emission is observed for these compounds as well as quenching of the "pseudo-local" acceptor emission. Transient absorption spectra show dialkylanilino-type radical-cation and dicyanoethylene-type radical-anion absorptions. These results show that intramolecular charge separation takes place in 1DA and 2DA. This was corroborated by time-resolved microwave conductivity measurements from which large excited-state dipole moments were found for both 1DA and 2DA. Time-resolved fluorescence spectroscopy revealed that in the charge-separated state in cyclohexane for 2DA, molecular folding takes place on a nanosecond timescale. For 1DA in cyclohexane, either charge separation takes place in a (fully) folded conformation or very rapid (subnanosecond timescale) folding takes place subsequent to charge separation. In addition to this difference in conformational behavior, the presence of the exocyclic double bond between the cyclohexyl-type rings results in efficient quenching of the anilino donor triplet state and acceleration of the charge recombination rate by a factor of 20.