Organic and organometallic molecules, which change their luminescence properties through a mechanical stimulus, such as emission wavelength and quantum yield, are called as mechanochromic or piezochromic materials. These functional molecules may be used as smart materials in the field of luminescent switches, mechanosensors, security papers, data storage, biological and healthcare applications. These materials are classified into two types, fluorescent and phosphorescent molecules. In this review, the recent progress in the phosphorescent mechanochromic materials, including pure organic molecules and metal complexes is highlighted. Their luminescence behaviors under mechanical force stimuli are shown and some critical concepts of molecular design for mechanoresponsive phosphorescent materials are also presented.

Recent progress in the mechanochromism of phosphorescent organic molecules and metal complexes

As a class of smart materials, mechanofluorochromic (MFC) luminogens have promising applications in mechanosensors, security papers, and optical storage primarily based on their alternation in emission behaviors in response to mechanical stimuli. It has been discovered that most molecules having aggregation-induced emission (AIE) exhibit mechanofluorochromism. As one of the essential AIE cores, cyanoethylene has been widely used to build MFC molecules. This review focuses on the latest advances in the mechanofluorochromism of cyanoethylene derivatives with AIE properties, which incorporates mechanistic studies on mechanofluorochromism and MFC luminogens based on cyanoethylene. We hope that this review will provide a clear outlook on these novel functional materials to a broad range of scientists within exclusive disciplinary areas and attract more researchers to devote themselves to this exciting research area.

Recent progress in the mechanofluorochromism of cyanoethylene derivatives with aggregation-induced emission

Systems that are intelligent have the ability to sense their surroundings, analyze, and respond accordingly. In nature, many biological systems are considered intelligent (e.g., humans, animals, and cells). For man-made systems, artificial intelligence is achieved by massively sophisticated electronic machines (e.g., computers and robots operated by advanced algorithms). On the other hand, freestanding materials (i.e., not tethered to a power supply) are usually passive and static. Hence, herein, the question is asked: can materials be fabricated so that they are intelligent? One promising approach is to use stimuli-responsive materials; these "smart" materials use the energy supplied by a stimulus available from the surrounding for performing a corresponding action. After decades of research, many interesting stimuli-responsive materials that can sense and perform smart functions have been developed. Classes of functions discussed include practical functions (e.g., targeting and motion), regulatory functions (e.g., self-regulation and amplification), and analytical processing functions (e.g., memory and computing). The pathway toward creating truly intelligent materials can involve incorporating a combination of these different types of functions into a single integrated system by using stimuli-responsive materials as the basic building blocks.

The Pathway to Intelligence: Using Stimuli-Responsive Materials as Building Blocks for Constructing Smart and Functional Systems

"Paper" has greatly contributed to the development and spread of civilization. Even in today's "digitalized" world, paper continues to play a key role in socioeconomic growth, as is evidenced by the growth in global paper consumption. Unfortunately, the use of paper has its cost in terms of the exhaustion of world's natural resources. Consequently, new, cost-effective technologies that preserve natural resources are required for this purpose. Functional materials have revolutionized the way people think about developing new technologies. Especially important in this regard are "smart reactive materials," which are capable of actively responding to external stimuli such as heat, light, mechanical stress, and specific molecular orientations. Moreover, functionalized chromogenic materials, which undergo reversible color switching upon external stimulation, have attracted great attention in the context of developing rewritable paper. Here, investigations of various materials and systems that are devised for use as rewritable paper are reviewed with the hope that the coverage will stimulate and guide future studies in this area.

Functional Materials and Systems for Rewritable Paper.

While manipulating the helicity of nanostructures is a challenging task, it attracts great research interest on account of its crucial role in better understanding the formation mechanisms of helical systems. For the supramolecular chirality in self-assembly systems, one challenge is how to understand the origin of supramolecular chirality and inherent helicity information on nanostructures regulated by functionality-oriented stacking modes (such as J- and H-aggregation) of building blocks. Herein, two-component hydrogels were prepared by phenylalanine-based enantiomers and achiral bis(pyridinyl) derivatives, where helical nanofibers with inverse handedness as well as controllable helical pitch and diameter were readily obtained through stoichiometric coassembly of these building blocks. The helix inversion was achieved by the transition between the J- and H-aggregation of bis(pyridinyl) derivatives, which was collectively confirmed by circular dichroism, scanning electron microscopy, Fourier transform in...

Controlling Supramolecular Chirality of Two-Component Hydrogels by J- and H-Aggregation of Building Blocks.

A small push-pull molecule involving a diphenylamine substituted by an oligo-oxyethylene chain is described. The compound exhibits aggregation-induced emission with solvent-dependent emission wavelength. Spin-cast deep-red amorphous films rapidly self-reorganize into colorless crystalline films which exhibit mechanofluorochromism and aggregation-induced second-harmonic generation.

/pdf/a-mechanofluorochromic-push-pull-small-molecule-with-6cnd368xtr.pdf

A Mechanofluorochromic Push–Pull Small Molecule with Aggregation‐Controlled Linear and Nonlinear Optical Properties

A small push–pull compound involving a methyl-diphenylamine donor block connected to a dicyanovinyl acceptor group through a 2,5-thienyl spacer has been synthesized (1). Comparison with a reference compound containing a triphenylamine block (2) shows that the replacement of a phenyl group by a methyl group has limited effects on the electronic properties of the molecule but induces major changes in the structure and electronic properties of the resulting material such as a ∼0.30 eV reduction of the optical band gap and fifty-fold increase of the hole-mobility. Results of X-ray diffraction on single crystals show that the replacement of a phenyl by a methyl group results in a change from head-to-tail to face-to-face arrangement of the dipolar molecules in the crystal. A preliminary evaluation of the potential of the new compound as a donor material in basic bilayer cells of 0.28 cm2 with C60 as the acceptor reveals a ca. 33% increase of the power conversion efficiency compared to the reference compound.

Manipulation of the band gap and efficiency of a minimalist push–pull molecular donor for organic solar cells

Molecular electron-acceptors based on benzodithiophene for organic photovoltaics

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Ping Liu

Author Tools

Chat about Author

Papers

A Mechanofluorochromic Push–Pull Small Molecule with Aggregation‐Controlled Linear and Nonlinear Optical Properties

Manipulation of the band gap and efficiency of a minimalist push–pull molecular donor for organic solar cells

Molecular electron-acceptors based on benzodithiophene for organic photovoltaics