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.

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.

对位环芳烃及其衍生物分子轨道的通过空间和通过键相互作用研究

应用改进的重叠模型多重散射Ｘα自洽场方法对对位环芳烃及其衍生物分子的分子轨道通过空间和通过键的相互作用进行了研究，讨论分子轨道相互作用对分子轨道能级顺序的影响以及不同的连接桥对分子轨道相互作用的影响，进一步应用过渡态理论方法计算对位环芳烃及其衍生物分子的分子轨道电离能，计算结果与实验结果符合较好。

Clusteroluminescence:A gauge of molecular interaction

Clusteroluminescence(CL)materials,as an emerging class of luminescent materials with unique photophysical properties,have received increasing attention owing to their great theoretical significance and potential for biological applications.Although much progress has been made in the design,synthesis and application of CL materials,there is still a big challenge in the emission mechanism.So far,throughspace interaction has been proposed as the preliminary mechanism of the corresponding clusterizationtriggered emission(CTE)effect,but a systematic theory is still needed.This review summarizes the current mechanistic understanding of CL materials including organic/inorganic small molecules,and polymers with/without isolated aromatic structures.In addition,some strategies to achieve high quantum yield,adjustable emission color,and persistent room temperature phosphorescence in CL materials are also summarized.At last,a perspective of the mechanism and application of CL materials are demonstrated,which inspire the researchers working on the development of new kinds of functional materials.

Emerging Clusteroluminescence from Complexes between Carbonyl-Based Polymers and Organic Base

The study of luminescence phenomena in non-conjugated systems,namely clusteroluminescence,has gained significant attention for the development of advanced luminescent materials.While conventional strategies to manipulate the luminescent performances are based on complicated chemical reactions.In contrast,nature employs complexation to modulate luminescence,inspiring researchers to adopt an engineering approach for the construction of efficient clusteroluminogens.In this work,we explore the complexationinduced clusteroluminescence of carbonyl-based polymers with nitrogen-containing organic bases,exemplified by polyamide,polyester,polycarbonate,and poly(monothiocarbonate).

Hydrogen bonding-induced oxygen clusters and long-lived room temperature phosphorescence from amorphous polyols

Developing non-conjugated luminescent polymers(NCLPs)with fluorescence and long-lived roomtemperature phosphorescence is of great significance for revealing the essence of NCLPs luminescence,which has gradually attracted the attention of researchers in recent years.Herein,polymethylol(PMO)and poly(3-butene-1,2-diol)(PBD)with polyhydroxy structures were prepared and their luminescence behaviors were investigated to reveal the clusteroluminescence(CL)mechanism.Compared with polyvinyl alcohol with non-luminescent behavior,PMO and PBD exhibit cyan-blue fluorescence with quantum yields of ca.12%and green room-temperature phosphorescence with lifetimes of ca.89 ms in the solid state.Both fluorescence and phosphorescence exhibit typical excitation-dependent CL behavior.Experimental and theoretical analyses show that the strong hydrogen-bonding interaction of PMO and PBD greatly promotes the formation of oxygen clusters and the through-space n-n interaction of oxygen atoms,enabling fluorescence and phosphorescence emission.Our results have enormous implications for understanding the CL mechanism of NCLPs and provide a new polymer design strategy for the rational design of novel NCLPs materials.

Manipulation of clusteroluminescence in carbonyl-based aliphatic polymers

Clusteroluminogens(CLgens),nonconjugated structures with visible luminescence at the clustering state,have recently received remarkable attention due to their great theoretical significance and practical values.In carbonyl-based aliphatic polymers,(n,π*)transition of carbonyl groups and the through-space interactions have been demonstrated to play an important role in their clusteroluminescence(CL)properties,but it is still a big challenge to manipulate their CL at the molecular level.In this work,six nonconjugated carbonyl-based polymers with different heteroatoms and steric hindrances were synthesized,and their photophysical properties were systematically studied.These polymers all showed CL but with different emission efficiency and wavelength.Experimental and theoretical studies indicated that the CL properties could be manipulated by changing the electronic structures of carbonyl groups and the rigidity of polymer chains.This work not only gains further insights into the CL mechanism but also provides reliable strategies to design and manipulate non-conjugated luminescent materials.