Multicolor Barcoding in a Single Upconversion Crystal
The synthesis of luminescent crystals based on hexagonal-phase sodium yettrium fluoride upconversion microrods is reported by A/P Liu Xiaogang's group. The synthetic procedure involves an epitaxial end-on growth of upconversion nanocrystals comprising different lanthanide activators onto the NaYF4 microrods. This bottom-up method readily affords multicolor-banded crystals in gram quantity by varying the composition of the activators. Importantly, the end-on growth method using one-dimensional microrods as the template enables facile multicolor tuning in a single crystal, which is inaccessible in conventional upconversion nanoparticles. These novel materials offer opportunities as optical barcodes for anti-counterfeiting and multiplexed labeling applications.
Single crystals of a coordination polymer containing an organic polymer ligand!
Prof. JJ Vittal’s group reported an organic polymer comprising cyclobutane rings and a coordination polymer blend together inside this 3D structure obtained in a photochemical dimerization reaction (Angewandte Chemie, 2014). The organic polymer can be depolymerized by the cleavage of cyclobutane rings in an SCSC manner. Read More
You can be made and broken in cycles, Mr. C-C Bond!
The cyclobutane ring can easily be made by solid-state [2+2] cycloaddition reaction. But can this be cleaved? Is it possible to make and break the C-C bond reversible? Can this be achieved in a single-crystal to single-crystal manner? Will this be accompanied by change in properties like photoluminescence? If so the applications for these types of systems are eminent in molecular switching and data storage. For more information see Prof. JJ Vittal’s recent Angewandte Chemie, 2014. Read More
Crystals dance during a reaction! Of course they are excited under UV light!
The self-propulsion of single crystals of three Zn(II) complexes under UV light has been discovered by Prof. JJ Vittal’s group (Angewandte Chemie, 2014). This visually appealing demonstration of the utility of molecular materials for conversion of energy to work. This has been considered as a hot paper by the journal and highlighted as their cover story of the issue. Read More
Distortional isomerism in polyrotaxane coordination polymers!
Of the four supramolecular isomers of coordination polymers synthesized, two have polyrotaxane structures which differ only in the relative positions of the wheel in the neighboring axle. They show different photoreactivity under UV light as well as sensing abilities of a number of organic nitro compounds. Prof. JJ Vittal’s group reported these findings in Angewandte Chemie, 2014. Read More
N-Annulated Perylene as An Efficient Electron Donor for Porphyrin-based Dyes: Enhanced Light-Harvesting Ability and High-efficiency Co(II/III)-based Dye-Sensitized Solar Cells
A new benchmark dye for dye-sensitized solar cell! In a recent Article published in JACS (http://pubs.acs.org/doi/abs/10.1021/ja409291g), A/P Wu Jishan and his local/international collaborators synthesized a series of N-annulated perylene substituted and fused porphyrin dyes, which showed largely enhanced light harvesting capability in particular in the near infrared region. As a result, one of the dyes exhibited a power conversion efficiency of around 11%, which is comparable and even slightly higher than that of the benchmark dye YD2-o-C8 under same conditions.
Observing High Pressure Chemistry in Graphene Bubbles
The above recent work by the team of Professor Loh Kian Ping has been chosen as a "Hot Paper" by the editors of Angewandte Chemie for its importance in a rapidly evolving field of high current interest. It is also highlighted in Chemistry World published by Royal Society of Chemistry.
Reference: C H Y X Lim, M Nesladek and K P Loh, Angew. Chem., Int. Ed., 2013, DOI: 10.1002/ange.201308682
Read more: Royal Society of Chemistry
Dibenzoheptazethrene Isomers with Different Biradical Characters: An Exercise of Clar’s Aromatic Sextet Rule in Singlet Biradicaloids
Extension of the Clar’s Aromatic Sextet Rule to the singlet biradicaloids!
In a recent Article published in JACS (http://pubs.acs.org/doi/abs/10.1021/ja410279j), A/P Wu Jishan and his local/international collaborators demonstrated that Clar’s Aromatic Sextet Rule can be further extended from the closed-shell polycyclic aromatic hydrocarbons to the open-shell polycyclic hydrocarbon systems, and provides an important guideline for the design of singlet biradicaloids with tailored biradical character and tunable optical, electronic and magnetic properties.
Order–disorder Transition in a Two-dimensional Boron–Carbon–Nitride Alloy
A team lead by Professor Loh Kian Ping reported the mixing and demixing of 2-D boron–nitrogen and carbon phases and found that energetics for such processes are modified by the metal substrate. The brick-and-mortar patchwork observed of stoichiometrically percolated hexagonal boron–carbon–nitride domains surrounded by a network of segregated graphene nanoribbons can be described within the Blume–Emery–Griffiths model applied to a honeycomb lattice.The isostructural boron nitride and graphene assumes remarkable fluidity and can be exchanged entirely into one another by a catalytically assistant substitution. Visualizing the dynamics of phase separation at the atomic level provides the premise for enabling structural control in a 2-D network for broad nanotechnology applications
Read more: Nature Communications
Congratulate Associate Professor Wu Jishan for being appointed as the Dean's Chair from 1st July 2014.
Congratulations to our graduate student Raghavender Medishetty for winning the Best Poster Presenter Award at the '6th-HOPE meeting with Nobel Laureates' March 11-15, 2014 in Tokyo, Japan.
Professor JJ Vittal has been invited to give a talk at the Gordon Research Conference on Crystal Engineering, June 1-6, 2014 at Waterville Valley, NH, USA. He was a discussion leader at the last GRC meeting in 2012 on the same topic.
Professor Lee Hian Kee has been placed in the technical trade journal The Analytical Scientist's (print circulation: 21,000; digital circulation: 58,000) "Power List: 100 Most Influential People in the Analytical Sciences"
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