Wenjing Li, Qi Wang, Yongshan Ma, Tianyi Jiang, Yanyan Zhu, Yuanyuan Shao, Cuizhen Sun and Junsen Wu
Self-organization has been regarded as a tool for the synthesis of well-defined organic nanostructures. Heterocyclic annulated perylene diimides are the subjects of considerable…
Abstract
Purpose
Self-organization has been regarded as a tool for the synthesis of well-defined organic nanostructures. Heterocyclic annulated perylene diimides are the subjects of considerable current research studies. The purpose of this study is to reveal the photophysical property, electronic structure and solid-state packing of O-heterocyclic annulated perylene diimide.
Design/methodology/approach
Asymmetrically five-membered O-heterocyclic annulated perylene diimide (OAPDI) was synthesized. Structure and purity of OAPDI were confirmed by 1H NMR, 13C NMR, IR and mass spectral techniques. Photophysical properties of OAPDI were studied using UV–vis absorption and fluorescence in both solution (CHCl3) and solid state. Scanning electron microscopic and atomic force microscopy were used to characterize the surface morphology of OAPDI. Conducting properties of the OAPDI were evaluated by current–voltage measurements. The compounds geometries were also optimized at 6-31G* using density functional theory.
Findings
The UV–vis absorption and fluorescence spectra of OAPDI in solution are blue-shifted in comparison with that of unsubstituted perylene bisimide. Solid-state UV–vis measurements of OAPDI indicate that it is capable of forming highly ordered structure. The non-covalent interactions, electrostatic attraction and p-p stacking moieties of OAPDI synergistically guide assembly and domain growth while maintaining the interpenetrating network of nanofibers in the solid film. The OAPDI gave higher current at −2.0 V (0.68 µA) and 4.0 V (1.0 µA).
Originality/value
This study will be helpful for exploring feasible routes to acquire soluble perylene diimides and well-defined organic nanostructures. Furthermore, such molecular tailoring approach would be helpful for designing and synthesizing novel organic semiconductive materials with excellent charge-transporting and light-emitting capabilities.
Details
Keywords
Moon Fai Chan, Tamadhir Al-Mahrouqi, Salim Al-Huseini, Maryam Al-Mukhaini, Manar Al Shehi, Firdous Jahan and Mohammed Al-Alawi
This cross-sectional online survey in Oman in April 2021 aimed to assess university students' resilience, stress levels and meaning during the COVID-19 pandemic and identify…
Abstract
Purpose
This cross-sectional online survey in Oman in April 2021 aimed to assess university students' resilience, stress levels and meaning during the COVID-19 pandemic and identify characteristic profiles.
Design/methodology/approach
A cross-sectional survey design was used to collect data from full-time students at one University in Oman. Outcomes included sociodemographic information, the brief resilience scale, the perceived stress scale-4 and the meaning in life questionnaire to explore the students' profiles.
Findings
A total of 964 students participated (response rate = 34.8%), of which 35% had low resilience scores. The average perceived stress, presence of meaning in life and search for meaning in life scores were 7.9 ± 2.3, 24.2 ± 6.9 and 24.9 ± 7.7, respectively. Cluster analysis identified three groups: low-risk and fewer impacts (cluster A, n = 503, 523%), moderate-risk and moderate impacts (cluster B, n = 160, 16.6%) and high-risk and more impacts (cluster C, n = 301, 31.2%). Cluster C students experienced more psychological problems and were at high risk during the pandemic.
Research limitations/implications
The respondents' honesty is a possible error that could influence the results. Low response rates limit its generalizability, and cause-effect relationships among mental health outcomes cannot be discerned.
Practical implications
This study identified three distinct groups of students, each with different levels of severity in their health problems. There is an increased need for education and counseling to support students during this period, and university management should focus on implementing personal precautionary measures and providing high-tech, user-friendly platforms for students to enhance their learning.
Originality/value
These findings suggest that tailored strategies should be developed to address the unique psychological needs of each group. The study provides important information for university management to understand the pandemic's psychological impact on students and develop effective interventions to support their well-being.