Proton-Template Synthesis of a П─Conjugated Macrocycle and Structure of its Ni_2(Ⅱ)—Complex

metol-free Robson -type macrocycle was synthesized for first time by proton-templation and from that the metal complexes were prepared.By X-ray study the structure of Ni(Ⅱ)-complex was characterized.

Synthesis and Electrical Conductivities of Fully Conjugated Schiff Base Macrocycles Containing 1,3,4-Oxadiazole

Conjugated Schiff base macrocycles containing 1,3,3-oxadiazole were prepared by [2 + 2] cyclic condensation of phenylenediamine with 2,5-bis(m-formyl-phenyl)-1,3,4-oxadiazole. These macrocycles with iodine or TCNQ produced stable charge-transfer complexes. The formation of complexes were identified by UV-Vis and FT-IR spectra.

Topologically engineering of π-conjugated macrocycles: Tunable emission and photochemical reaction toward multi-cyclic polymers

The topology of conjugated macrocycles had significant impacts on their photo-physical and photochemical properties.Herein,a series ofπ-conjugated macrocycles with diverse topology were synthesized via intramolecular McMurry coupling.Their chemical structure and macrocyclic topology were unambiguously confirmed via NMR,MALDI-TOF mass spectra,crystal analysis and scanning tunneling microscopy(STM).Depending on the structural topology and structural rigidity,these cyclic compounds display obviously distinctive emission behavior and photochemical reactions in the solution and in the solid state.Monocyclic phenylene vinylene macrocycle(denoted as MST)exhibiting aggregation-induced emission behavior,was more vulnerable to photo-cyclization in solution and triplet sensitizer promoted photodimerization due to lower strain and more flourishing intramolecular motions.After UV light irradiation,relatively more flexible MST could yield the anti-dimer via triplet excimer on the HOPG surface confirmed by STM investigation.By contrast,highly constrained bicyclic analogue(named as DMTPE)with central tetraphenylethene core,displayed high emission quantum yields of 68%both in solution and in the solid state,and was relatively inert to photochemical reactions and yield syn-dimer on the surface via singlet excimer involved[2+2]photo-dimerization.Based on the solution-mediated photo-polymerization of MST moiety,multicyclic porous carbon-rich ribbon connected with four-membered ring was successfully constructed and validated via STM imaging.

Synthesis and Properties of Ferrocene Conjugated Macrocycles with Illusory Topology of the Penrose Stairs

Polyferrocene macrocycles hold immense potential in the fields of molecular electronics and electrochemistry,primarily due to their multiple metal centers.However,developing highly efficient synthetic strategies for constructing these rings remains a significant challenge.In this study,we successfully synthesized triferrocenyl macrocycles using Pt-mediated coupling strategy and determined their configuration using single-crystal X-ray diffraction analysis,revealing a structure reminiscent of the Penrose Stair.We comprehensively investigated the macrocycle’s structure,photophysical properties,and employed density functional theory(DFT)calculations to gain further insights.Notably,this macrocycle exhibits several advantageous features,including a flexible structure,good solubility,and a highly efficient synthetic pathway.

Photoactive donor-acceptor conjugated macrocycles:New opportunities for supramolecular chemistry

The design and synthesis of photoactive macrocyclic molecules continue to attract attention because such species play important roles in supramolecular chemistry as well as photoelectronic applications.Donoracceptor(D-A)conjugated macrocycles are an emerging class of photoactive molecules due to their D-A conjugated structural characteristics and tunable optical properties.In addition,the well-defined cavities in such D-A macrocycles endow them with versatile host-guest properties.In this review,we provide a comprehensive summary of D-A conjugated macrocycle chemistry,detailing recent progress in the area of synthetic methods,optical properties,host-guest chemistry and applications of the underlying chemistry to chemical sensors,bioimaging and photoelectronic devices.Our objective is to provide not only a review of the fundamental findings,but also to outline future research directions where D-A conjugated macrocycles and their constructs may have a role to play.

Facile synthesis of azobenzene-embedded conjugated macrocycles for optically switchable single-crystal transistors and tunable supramolecular assemblies

A series of newπ-conjugated macrocycles(AzoM-n-E,n 1–3)incorporating=azobenzene units have been synthesized by a facile strategy in one-pot reaction.The resultant azobenzene-embedded macrocycles feature intrinsic photoresponsive behaviors and intriguing supramolecular assembling properties.The smallest macro-cycle AzoM-1-E with a rigid planar conjugated backbone structure is used to prepare the single crystal transistors,showing reversible optical tunability.The moderate size macrocycle AzoM-2-E assembles into a dimer in the form of interpenetration throughπ-πstacking between azobenzene units.The largest macrocycle AzoM-3-E with enhancedflexibility can adaptively assemble with various types of electron-deficient guests accompanied by distortion of azobenzene.Typically,AzoM-3-E assembles with the planar F4-TCNQ to form a tetragonal geometry by C-F⋅⋅⋅π and π-π interactions,while the assembly with ellipsoidal C70 viaπ-πinteractions induces AzoM-3-E to form a boat-shaped geometry.This work will shed new light on the development of functional conjugated macrocycles in organic electronics.

Side-Chain Type Ferrocene Macrocycles

A class of side-chain type ferrocene macrocycles with a radially conjugated system is introduced in this study.The stereo configurations of these ferrocene rings were determined through single-crystal X-ray diffraction analysis.Notably,in the solid state,the ferrocene rings exhibit a distinctive herringbone stacking pattern imposed by a ferrocene-to-ring host−guest interaction.Through UV−vis absorption spectroscopy,electrochemical measurements,and theoretical calculations,valuable insights into the electronic properties of these rings were obtained.In addition,the single crystal of macrocycle A_(2)B demonstrates a second-order nonlinear optical response.As a class of organometallic nanorings,this work holds great potential for further exploration in the fields of organometallic chemistry,molecular electronics,and host−guest chemistry.

Accelerating the thermal fading rate of photochromic naphthopyrans by pillar[5]arene-based conjugated macrocycle polymer

A new micro-spherical conjugated macrocycle polymer(P[5]-TFB-CMP)was prepared by the condensation reaction between dihydrazide functionalized pillar[5]arene and 1,3,5-triformylbenzene under ambient conditions.P[5]-TFB-CMP exhibits large surface area with excellent thermal stability and has been used as additive to prepare composite PMMA film of photochromic naphthopyrans.The results showed that the addition of P[5]-TFB-CMP could dramatically accelerate the thermal fading rate of the photochromic composite film by up to 12 times.This is a new strategy to overcome the drawback of the matrix effect.

A novel conformationally adaptive macrocyclic tetramaleimide with flipping pyrene sidewalls

The synthesis,structure,and properties of pyrene-based conformationally adaptive macrocycles are described.This new type of conformationally adaptive macrocycle was constructed through Perkin reaction,followed by imidization.By changing the condensation partner as the linking unit,a family of conjugated macrocycles with different sizes of the cavity was synthesized,which provide a simple and modular synthetic strategy towards the conformationally adaptive macrocycles.Furthermore,the macrocycles provide two well-defined conformations through flipping pyrene subunit,which were unambiguously determined by single-crystal X-ray diffraction analysis.The conformational interconversion barrier was determined by density functional theory(DFT)calculations.This new macrocycle also demonstrated unique properties,such as vapochromic behavior and aggregation emission enhancement effect.Furthermore,we have also investigated the effect of the linker on the shape and photophysical properties of the resulting macrocyclic products.