英语翻译In this organogel structure,the p–p stacking interaction

英语翻译
In this organogel structure,the p–p stacking interactions
among the HPB moieties,the hydrogen-bonding interactions
between the urea moieties,and the van der Waals forces
between the long alkyl chains cooperatively stabilized the
aggregate structure; these are well-known interactions in gel
systems.2a,5 Specifically to clarify the effect of the hydroxyl
group in the HPB unit on gelation,we also designed and
synthesized reference compound 2,which does not contain an
adjacent hydroxyl group and thereby cannot induce its planar
keto tautomer upon excitation.As expected,2 was not gelled
but precipitated under such conditions that brought about the
gelation of 1 because the molecular stacking between the HPB
units was interfered with due to the lack of planarity.Therefore,
it is presumed that the planarity of HPB from intramolecular
hydrogen bonding is one of the driving forces for gelation.
Compound 1 is weakly luminescent in DMF solution [the
absolute quantum yield measured in integrating sphere (FF)
was 1.4%,at 1.71 \2 10\35 M]; however,it becomes highly
fluorescent in the gel state (FF = 34.7%) by aggregationinduced
emission (AIE) as shown in Fig.2(A).10 When 1
aggregated in the DMF/toluene mixture,its fluorescence
increased significantly [Fig.2(B)].Interestingly,absorption
of the aggregates (343 nm) in a such solution mixture was
blue-shifted from that of the solution (360 nm).The blue-shift
is unusual because aggregation usually induces a red-shift.In
addition to the blue-shift of the lmax,the emission maximum
was also blue-shifted (from 414 to 402 nm for the enol form
and from 541 to 519 nm for the keto form) with remarkable
emission enhancement of the keto tautomer upon aggregation.

在这一有机凝胶结构中,π-π在HPB分子部分中的重叠互作用,在尿素分子部分之间的氢键结合互作用,以及长烷基链之间的范德瓦尔斯力合作,使得聚集结构稳定化,这些是凝胶系统中众所周知的互作用.2a,5 专门为了澄清HPB单元中的羟基基团对凝胶作用的影响,我们还设计并合成了参考化合物2,它不含邻近的羟基基团,因而不能在激励条件下感生平面的酮互变异构体.如预料的那样,化合物2不是凝胶的,但是在引起凝胶剂1凝胶作用这样的条件下是沉淀的,因为在HPB单元之间的分子重叠由于缺乏平面性而受到了干扰.因此,我们假定来自于分子内氢键结合的平面性是凝胶作用的驱动力之一.
化合物1在DMF溶液中是弱荧光的[在1.71×10－5M下,用积分球(φF)测量的绝对量子产率为1.4％]；可是在凝胶态中,由于聚集感生发射（AIE）它就变成高度荧光的（φF＝34.7％）,就如图2(A)所示的那样.10 当凝胶剂1在DMF/甲苯混合物中聚集时,它的荧光明显增加[图2(B)].有意思的是,在这样的溶液混合物中的聚集体的吸收（343nm）从该溶液聚集体的吸收（360nm）向蓝色偏移.这种蓝色漂移是不寻常的,因为聚集作用通常都是感生红色偏移.除了λmax的蓝色偏移外,发射最大值也是蓝色偏移的（对烯醇形式来说从414到402nm,而对酮形式来说从541到519nm）,酮互变异构体在聚集作用下发射有明显提高.