STUDY ON THE THROUGH-SPACE AND THROUGH-BOND INTERACTIONS IN TRICYCLO 4,2,2,2 DODECADIENE-1.5

Through-space interactions of pi orbiatl and sigma orbital in molecule tricycle 4,2,2,2,dodecadiene -1.5 were studied by means of DV-X alpha SVF method using a model molecule that consists of two ethylenes with interdeck distance D. The results show the through-space interactions of the title molecule decrease with the increasing of D,the through-space interactions of pi orbital are larger than that of sigma orbital. Furthermore, through-bond interactions of the pi orbtial and sigma orbital were analyzed basing on the calculations of the electronic structure of the title molecule. Both through-space and through-bond interactions are Large and,the net interactions are small. The calculated ionization potential energies of the title molecule which were obtained by transition-state procedure are in good agreement with the PE spectroscopy.

The superiority of nonconjugated structures in fluorescence:through-space vs.through-bond charge transfer

Constructing charge transfer(CT)state by introducing donor(D)and acceptor(A)is an efficient strategy to regulate the photophysical properties of luminescent materials.Traditional CT-type luminophores are built onπ-conjugated fused-ring structures,which always show hybrid CT/locally excited(LE)states and luminescence quenching effect in the aggregate state.In this work,eight conjugated biphenyl(BP)and nonconjugated diphenylmethane(DPM)derivatives with different donors and acceptors are synthesized to investigate the CT properties.Systematic photophysical characterization and theoretical calculation demonstrate that the through-space CT(TSCT)in nonconjugated DA-DPM exhibit superior photophysical performance than the conjugated DA-BP with through-bond CT(TBCT),the main manifestations are as follows:(1)TSCT luminophores produce longer maximum emission wavelength(λ_(em))than the corresponding TBCT ones.For example,the longest λ_(em)of DMA-CN-DPM(DMA,dimethylamino)is 621 nm but the corresponding λ_(em)of DMA-CN-BP is only 480 nm.(2)TSCT-based DA-DPM demonstrates more sensitive responsiveness to environmental stimuli such as temperature and polarity.(3)Complete separation of the the highest occupied molecular orbital(HOMO)and the lowest unoccupied molecular orbital(LUMO)distribution exists in all kinds of conformation of DA-DPM,which was hard to realize in conjugated DA-BP.

Fjord-Type AIEgens Based on Inherent Through-Space Conjugation

Through-space conjugation(TSC)is a noncovalently electronic interaction that is emerging as a potential complement to through-bond conjugation(TBC)-based strategies for constructing luminescent materials.However,the design of efficient luminogens based on TSC is currently challenging due to a lack of established structure-property understanding.This is particularly true in the case of luminogens displaying aggregation-induced emission(AIE)effects.In this work,three terphenyl derivatives were prepared,and their photophysical properties were systemically studied.It was found that relative to the corresponding m-and p-linked analogues,the electronic interaction of TBC is weakened while the strength of TSC is commensurately enhanced in the constitutional isomer containing an o-linked fjordtype subunit.Within this set of luminogens,the presence of a fjord-type arrangement promotes a transformation from aggregation-caused quenching to AIE.Further investigations involving congeneric quaterphenyl and pentphenyl isomers support the universality of the fjord-type unit as a framework for synthesizing AIE-active luminogens(AIEgens)with inherent TSC.This work not only provides a novel set of AIEgens but also establishes the utility of TSC in controlling the photophysical properties of nonconventional and twisted luminogens.

Construction of chiral through-space luminophores via symmetry breaking triggered by sequenced chlorination

The construction of molecular chirality is crucial for exploring novel luminophores with chiroptical properties.Classic asymmetric synthesis of chiral center or axial is not powerful enough on through-space architecture.Accessible methodologies for breaking molecular symmetry could be promising but remain less investigated.Herein,we report a novel methodology for constructing chiral through-space luminophores via simple chlorination on bridged carbazole motifs.The chlorination breaks the molecular symmetry and thus results in molecular chirality by eliminating the mirror plane or rotating axis.Interestingly,continuous multiple chlorinations can rebuild and break the symmetry of the skeleton in succession.Several chiral and achiral isomeric analogues are synthesized and characterized with impressive chiroptical properties.Results of chiral high performance liquid chromatography(HPLC),single-crystal X-ray diffraction,kinetic racemization,and chiroptical property investigation demonstrate the effectiveness of our rational design strategy.It provides a feasible methodology for exploring novel chiral luminescent materials based on versatile though-space skeletons.

Acceptor modulation for improving thermally activated delayed fluorescence emitter in through-space charge transfer on spiroskeletons

Through-space charge transfer(TSCT)is regarded as an effective way to develop thermally activated delayed fluorescence(TADF)emitters.Based on this strategy,many molecular frameworks have been proposed,among which spirobased scaffolds have been extensively studied due to their unique advantages.In this work,we developed three emitters SPS,SPO,and SPON,which were constructed with the same donor and various acceptors to explore the influence of acceptor modulation at the C9 position of fluorene for spirostructure TSCT emitters.The results show that the acceptor with too weak electronwithdrawing ability will cause the emitter to not have TADF properties,while the acceptor with too much steric hindrance will weaken the face-to-faceπ-πstacking interaction between donor/acceptor(D/A).Since SPO balances the electron-withdrawing strength and steric hindrance of the acceptor,it achieves the highest external quantum efficiency(EQE)of 17.75%.This work shows that appropriate acceptor selection is essential for the TADF properties and high efficiency of the spirobased scaffold TSCT emitter.

Controllable Secondary Through-Space Interaction and Clusteroluminescence

Nonconjugated clusteroluminogens(CLgens),such as proteins and polystyrene,have become increasingly important in photophysics.They show many advantages over traditional conjugated dyes with fused aromatic rings in biological applications.However,CLgens have historically been unheeded because of their weak visible emissions in the aggregate state,namely clusteroluminescence(CL).Changing the electronic structures of CLgens by precisely regulating the intramolecular throughspace interaction(TSI)to improve their photophysical properties remains an enormous challenge.Herein,we propose a general strategy to construct a higher-level intramolecular TSI,namely secondary TSI constructed by the primary TSI and a TSI linker,in multi-aryl-substituted alkanes(MAAs).By introducing methyl and phenyl into 1,1,3,3-tetraphenylpropane,the modified MAAs show efficient CL with high luminescence quantum yield(-40%)and long emission wavelength(-530 nm).Then,comprehensive experiments and theoretical studies demonstrate that molecular rigidity and overlap of subunits play pivotal roles in improving these hierarchical TSIs.This work not only provides a feasible strategy to achieve controllable manipulation of hierarchical TSIs and CL but also establishes comprehensive TSI-based aggregate photophysics.

Synthesis and Properties of a Through-Space Interacting Diradicaloid

Knowledge about electronic structures is important to gain an understanding of the unique functional properties of diradicaloids.In this study,we synthesized and characterized a diradicaloid in which two phenalenyl radical sites are coupled antiferromagnetically via a through-space interaction.The results of quantum chemical,physicochemical(^(1)H NMR,electronic absorption,cyclic voltammetry,SQUID,ESR),and chemical reactivity studies show that this diradicaloid has singlet diradical character.An assessment of the nature of the bonding interaction between two radical sites in this species using DFT calculations demonstrates that a small spatial overlap between the two SOMOs in this diradicaloid provides an efficient electron exchange path for the singlet state to be substantially lower in energy than the triplet state.

Through-Space Conjugation: A Thriving Alternative for Optoelectronic Materials

Efficient electronic coupling is the key to constructing optoelectronic functionalπsystems.Generally,the delocalization ofπelectrons must comply with the framework constructed by covalent bonds(typicallyσbonds),representing classic through-bond conjuga-tion.However,through-space conjugation offers an alternative that achieves spatial electron communica-tionwith closely stacked π systems instead of covalent bonds thus enabling multidimensional energy and charge transport.

Through-space charge transfer blue polymers containing acridan donor and oxygen-bridged triphenylboron acceptor for highly efficient solution-processed organic light-emitting diodes

Three kinds of through-space charge transfer(TSCT)blue polymers containing non-conjugated polystyrene backbone together with spatially-separated acridan donor and oxygen-bridged triphenylboron acceptors having different substituents of tert-butyl,hydrogen and fluorine are designed and synthesized.The designed TSCT blue polymers possess photoluminescence quantum yields up to 70%in solid-state film,single-triplet energy splitting below 0.1 eV,and typical thermally activated delayed fluorescence(TADF)effect.Meanwhile,the resulting polymers exhibit aggregation-induced emission(AIE)effect with emission intensity increased by up to^27 folds from solution to aggregation state.By changing the substituent of acceptors to tune the charge transfer strength,blue emission with peaks from 444 to 480 nm can be realized for the resulting polymers.Solution-processed organic light-emitting diodes based on the polymers exhibit excellent device performance with Commission Internationale de L’Eclairage(CIE)coordinates of(0.16,0.27),together with the maximum luminous efficiency of 30.7 cd A-1 and maximum external quantum efficiency of 15.0%,which is the best device efficiency for blue TADF polymers.

Through-space charge transfer polymers for solution-processed organic light-emitting diodes

Through-space charge transfer(TSCT)polymers are an attractive class of luminescent polymers with spatial donor/acceptor architecture and thermally activated delayed fluorescence effect,different from conventional luminescent polymers with conjugated donor-acceptor structure and through-bond charge transfer emission.Their emission comes from the intramolecular charge transfer by through-space pathway because the donor and acceptor segments are spatially proximate to each other in each repeating unit but are physically separated by nonconjugated polymer backbone.In this review,recent advances in TSCT polymers with linear,bottlebrush,and dendritic architectures are presented,with the focus on their molecular design,photophysical behavior,and device performance.We hope that this review shall provide a useful insight of new luminescent polymers with TSCT effect for use in solution-processed organic light-emitting diodes.

Recent advances of folded tetraphenylethene derivatives featuring through-space conjugation

Through-space conjugated molecules are interesting building blocks for the construction of functional materials that allow multi-dimensional transport of carrier and energy.However,the well explored through-space conjugated molecules are quite limited,which defers their structure-property correlation establishment and wide-scale application.In this review,we introduce a kind of newly-emerging folded tetraphenylethene derivatives featuring through-space conjugation.Their synthesis,crystal and electronic structures,and optical properties are described,and their representative applications as bipolar charge-transporting materials in organic light-emitting diodes and as single-molecule wires in molecular devices are presented,which are anticipated to provide guidance for the further expansion of through-space conjugated systems.

Carbazole ring: A delicate rack for constructing thermally activated delayed fluorescent compounds with through-space charge transfer

Three carbazole derivatives, Ac PTC, Px PTC and Pt PTC, consisting of two 9,9-dimethyl-9,10-dihydroacridine,phenoxazine or phenothiazine donor groups and one diphenyltriazine acceptor group fixed at 1,8,9-positions of a single carbazole ring via phenylene, are designed and synthesized. X-ray diffraction analysis of Ac PTC reveals that there exist multiple π-π interactions between the donor and acceptor groups to form a sandwich-like structural unit with edge-to-face interaction model. The compounds thus show obvious thermally activated delayed fluorescence with through-space charge transfer character and possess considerable photoluminescence quantum yields of up to 73% in doped films with sky-blue to yellow emissions. The solution-processed electroluminescent devices achieve the highest maximum external quantum efficiencies of 10.0%, 11% and 5.6% for Ac PTC, Px PTC and Pt PTC, respectively, with small efficiency roll-offs.

Ⅰ期非小细胞肺癌患者肺穿刺活检是否增加胸膜复发和气腔播散的风险

近年来,随着肺结节的比例升高,术前经皮肺穿刺活检或经支气管镜活检越来越受到重视。大量临床证据也证实,Ⅰ期非小细胞肺癌(non-small cell lung cancer,NSCLC)的肺穿刺活检是安全可行的。但是,由于肺磨玻璃结节的组织学特点,与实性结节相比穿刺时更容易发生出血或咳嗽,肿瘤细胞在血流或气流冲击下可能会沿着肺泡壁或针道种植,导致胸膜复发和气腔播散(spread through air spaces,STAS),尤其是胸膜下结节合并有脏层胸膜侵犯和淋巴细胞浸润时需要慎重选择。

无刷双馈风力发电机低电压穿越控制策略研究

针对无刷双馈风力发电系统,稳态时,采用基于空间矢量调制(Space Vector Modulation,SVM)的直接功率控制(Direct Power Control,DPC)技术。在电网电压对称跌落条件下,理论分析功率绕组磁链与控制绕组电压的关系,对于故障期间控制绕组会产生较大的过电流,严重时可能损害变流器功率器件的问题,在原有的控制方案中引入前馈控制。通过将可观测的功率绕组电流进行微分运算后得到反映控制绕组反电势的直接干扰量,将其经前馈控制器引入到控制电压的参考值端,形成一种基于前馈控制的SVM-DPC复合控制。仿真结果表明,基于功率绕组电流微分前馈控制的复合控制策略可以在一定程度上抑制控制绕组过电流,能为无刷双馈风力发电机实现低电压穿越提供参考。

肺癌气道播散的影像学研究进展

肺癌气道播散(STAS)是指肿瘤细胞以微乳头状细胞团、实性细胞巢或单个细胞等形式存在于主瘤体之外的气道中。随着肺癌研究的不断深入,预测肺癌STAS在诊治和预后中有重要的价值,因此在2015年世界卫生组织将其确定为肺腺癌的一种新的侵袭方式。近年来,利用影像学方法预测STAS的有无已经成为研究的热点。目前相关研究的结果已证实了影像学预测STAS的可行性,进一步深入的研究对发现更加可靠和准确的影像学预测方法十分必要。本文就STAS的病理学、临床意义及影像学方面的研究进展予以综述。

肺腺癌气腔播散影像学研究进展

2015年,世界卫生组织明确指出气腔播散(STAS)是肺癌的一种新型的播散方式。大量研究结果显示肿瘤实性成分越多,直径越大意味着出现STAS机率越大。本文拟从STAS发生机制、病理诊断及影像学表现等方面作一综述。

肺腺癌病理分级与肿瘤气道播散及脉管侵犯的相关性

目的:探究新版肺腺癌分级系统与气道播散及脉管侵犯的相关性。方法:回顾性分析四川省肿瘤医院2021年行肺癌手术且经术后病理确认浸润性肺腺癌的患者,采集患者临床及病理信息,根据IASLC发布的新浸润性肺腺癌分级标准将患者分为3组,低分化组(III级)、中分化组(II级)、高分化组(I级)。分析患者术后临床病理特征及基因型与分级的关系。结果:单因素分析显示,低分化肿瘤与老龄、男性、实性结节、肺叶切除术和侵袭性特征(肿瘤大小、淋巴结转移、分期、气道播散、脉管浸润、胸膜浸润)相关。且与中高分化肿瘤具有显著性差异(P<0.05)。多因素分析显示肿瘤影像学特征、气道播散、脉管侵犯是独立因素。对行基因检测人群分析,EGFR突变在三组间无统计学意义(P>0.05)。余基因型无法评估与分级相关性。结论:低分化肿瘤与气道播散及脉管侵犯相关。

气道播散与肺腺癌临床病理危险因素相关性分析

目的探讨气道播散(STAS)在肺腺癌中的意义及与临床病理危险因素的相关性。方法选取2015-10—2022-10在涿州市医院和河北一洲肿瘤医院接受手术切除术的228例肺腺癌患者为研究对象。通过苏木精-伊红染色判断STAS情况;分析STAS与临床病理危险因素的相关性。结果STAS与性别、吸烟、组织学类型、T分期、淋巴结转移、脉管神经侵犯和肺膜侵犯相关(P<0.05);与年龄无关。生存分析发现,伴STAS的总生存时间低于无STAS的患者(P<0.05)。结论STAS在肺腺癌预后中具有重要的价值,STAS和临床病理危险因素相结合可以提高肺腺癌预后评估的准确性和可靠性,建议在常规病理报告中纳入此项指标,为肺腺癌患者的治疗和预后评估提供更为科学、全面的依据。

不同内固定术治疗创伤性胸腰椎骨折的效果对比

目的:比较不同内固定术治疗创伤性胸腰椎骨折的效果。方法:选取2021年1月-2022年1月仁怀市中医院收治的胸腰椎骨折患者100例作为研究对象,采用随机数字表法分为对照组和观察组,各50例。对照组采用经皮入路椎弓根钉棒系统内固定治疗,观察组采用经椎旁肌间隙入路椎弓根钉棒系统内固定治疗。比较两组围术期指标及骨折愈合时间、骨代谢活性指标、围术期并发症、疼痛程度与功能障碍情况。结果:两组手术时间、术中出血量比较,差异无统计学意义(P>0.05);观察组住院时间、骨折愈合时间短于对照组,差异有统计学意义(P<0.001)。术后1个月,两组骨钙素(BGP)、骨保护素(OPG)水平高于术前,Ⅰ型胶原C端肽(CTX-Ⅰ)水平低于术前,差异有统计学意义(P<0.05);术后1个月,观察组BGP和OPG水平高于对照组,CTX-Ⅰ水平低于对照组,差异有统计学意义(P<0.05)。观察组并发症发生率低于对照组,差异有统计学意义(P=0.029)。术后3个月,两组视觉模拟评分、Oswestry功能障碍指数均降低,观察组低于对照组,差异有统计学意义(P<0.001)。结论:两种手术方式均具有良好的预后效果,但经椎旁肌间隙入路的椎弓根钉棒系统内固定方法效果更加显著,在提高患者围术期指标与提高骨代谢活性指标的同时,还可减少并发症,减轻疼痛程度,值得推广。

经椎旁肌间隙入路结合伤椎置钉内固定系统对胸腰椎骨折的治疗效果及对患者椎体前缘高度和伤椎楔变指数的影响

目的探讨经椎旁肌间隙入路结合伤椎置钉内固定系统对胸腰椎骨折的治疗效果及对患者椎体前缘高度和伤椎楔变指数的影响。方法选取2019年1月至2022年1月海东市平安区中医院收治的56例胸腰椎骨折患者作为研究对象,根据手术方式分为A组与B组,每组28例。A组采用经椎旁肌间隙入路结合伤椎双侧置钉内固定治疗,B组采用经椎旁肌间隙入路跨伤椎常规置钉治疗,比较两组基本手术指标、脊柱功能恢复情况、并发症发生情况、生命质量。结果A组下床活动及骨折愈合时间短于B组(P<0.05);两组术中出血量比较差异无统计学意义;术后3个月,两组椎体前缘高度、IVW均高于术前,Cobb角、ODI评分均低于术前,且A组椎体前缘高度、IVW高于B组,Cobb角、ODI评分均低于B组,差异有统计学意义(P<0.05)。A组并发症发生率低于B组,差异有统计学意义(P<0.05)。术后3个月,两组生理机能、生理职能、情感职能、精神健康、生命活力、社会功能、躯体疼痛、总体健康评分均高于术前,且A组均高于B组,差异有统计学意义(P<0.05)。结论经椎旁肌间隙入路结合伤椎双侧置钉内固定治疗胸腰椎骨折患者疗效显著,可有效改善患者脊柱功能,提高患者生命质量,减少并发症,值得临床推广应用。