Dipolar Quinoidal Acene Analogues as Stable Isoelectronic Structures of Pentacene and Nonacene
In a recent article published in Angew. Chem. Int. Ed., 2015, 54, 14412 (http://onlinelibrary.wiley.com.libproxy1.nus.edu.sg/doi/10.1002/anie.201507573/pdf ), Dr. Chi and her co-workers synthesized quinoidal thia- acene analogues as the respective isoelectronic structures of pentacene and nonacene and an unusual 1,2-sulfur migration was observed during the Friedel-Crafts alkylation reaction. They display a closed-shell quinoidal structure in the ground state with a distinctive dipolar character. In contrast to their acene isoelectronic structures, both compounds are very stable because of existence of more aromatic sextet rings, dipolar character, and kinetic blocking. They exhibit unique packing in single crystals due to balanced dipole-dipole and [C-H•••π]/[C-H•••S] interactions.
Z-Shaped Pentaleno- Acene Dimers with High Stability and Low Band Gap
Dr. Chi’s group reported a new strategy to stabilize reactive acenes by fusion of an anti-aromatic pentalene unit onto the zig-zag edges of two acene units to form a Z-shaped acene dimer, which turned out to be extremely stable and show a small energy gap due to intramolecular donor-acceptor interaction. The stability of pentaleno- tetracene dimer solution is up to 54 days in ambient air and light conditions. X-ray crystallographic analysis revealed their unique geometry and 1D slip-stack columnar structure.
Reference: Angew. Chem. Int. Ed. 2016 (http://onlinelibrary.wiley.com.libproxy1.nus.edu.sg/doi/10.1002/anie.201508919/pdf
Self-consistent reaction field (SCRF) methods based on multiple expansions
Self-consistent reaction field (SCRF) methods based on multiple expansions are the most popular approaches in incorporation solvation effect in quantum chemical calculations. The Onsager SCRF model was first implemented in the most popular and widely used Gaussian series of programs by Wong, Frisch and Wiberg. The implementation and application of this SCRF method were described in Journal of American Chemistry Society (1991, 113, 4776-4782). The total citations of this landmark paper have reached 1000 recently!
Multiphoton harvesting metal–organic frameworks
Usually multiphoton harvesting property exhibited by the organic molecules in the solution, is quenched in the solid state due to aggregation. However, efficiently luminescent materials in the solid-state form are highly preferable in many photonic applications such as upconversion lasing and light emission due to a higher resistant to photobleaching. By rational choice of ligands with high second hyperpolarizability, MOFs with large nonlinear optical response (up to direct absorption of four photons at 1500 nm) has been reported for the first time by Hong Sheng Quah, Weiqiang Chen, Martin K. Schreyer, Hui Yang, Ming Wah Wong, Wei Ji, and Jagadese J. Vittal in the recent issue of Nature Communications (Vol. 6, Article No. 7954, 2015, doi:10.1038/ncomms8954).
Singaporean Inorganic Chemistry Symposium 2015
The inaugural Singaporean Inorganic Chemistry Symposium (SICS2015) was held at University Town on the 29th of July, 2015. The symposium featured researchers from over thirteen inorganic based research groups from both the NUS Department of Chemistry and the NTU Division of Chemistry and Biological Chemistry in attendance. A wide range of inorganic research was showcased by eleven speakers, varying from medicinal chemistry to catalysis to fundamental main group chemistry. ‘Best Speaker’ awards were presented to Mr Kennard Gan (NTU), Ms Shi Xiaoyan (NTU) and Mr Kelvin Lim (NUS). The SICS2015 organising committee would like to thank the NUS Department of Chemistry for their support in organising this event. More photos.
Quacquarelli Symonds (QS) World University Rankings 2015
NUS Chemistry has been ranked 7th internationally and 1st in Asia in the latest Quacquarelli Symonds (QS) World University Rankings by Subject. Read More.
We welcome Class of ’62 Visiting Professor Rodney Scott Ruoff.
Congratulations to Dr Ge Shaozhong for being awarded the 2015 NUS Young Investigatorship.
Congratulations to Prof Loh Kian Ping for winning the Provost's Chair (Tenable for 3 years from July 2015). Prof Loh was awarded the 2014 President’s Science Award for his outstanding research on graphene chemistry. His research effort on advanced carbon materials is internationally acclaimed and has contributed to Singapore’s and NUS’ position as world leader in this research area.
The Department has just established a research collaboration with its counterpart at the King Fahd University of Petroleum & Minerals (KFUPM), Dhahran, Saudi Arabia. Under the collaboration, six projects involving faculty members from both departments will receive funding of S$1.1 million over three years. From our department, Professors Lu Yixin, Richard Wong and Lee Hian Kee, and Associate Professors Chuah Gaik Khuan, Han Vinh Hyunh and Stephan Jaenicke will be involved in the collaboration with their colleagues from KFUPM on environmental analytical chemistry, catalysis, nanostructured materials and computational electrochemistry.