Publications

Interaction of gold nanorods with cysteine as well as 3-mercaptopropionic acid (MPA) has been investigated by isothermal titration calorimetry (ITC), in combination with electronic absorption spectroscopy and electron microscopy. The assembly process with MPA shows two steps, the first due to the binding of MPA to gold nanorods through the sulfur atom, and the second due to assembly of the MPA capped gold nanorods through the formation of cyclic hydrogen bonded dimers between the MPA molecules. In the case of cysteine only a single step is observed in ITC, due to the binding of the molecules to gold nanorods.

The nature of the phase transitions of Bi2MoO6 has been investigated by the combined use of X-ray diffraction and X-ray absorption spectroscopy. The distorted MoO6 octahedra in the low-temperature form are shown to undergo further distortion in the intermediate-temperature form before transforming to MoO4 tetrahedra in the high-temperature phase.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The low temperature phase of single crystals of Nd$_{0.5}$Ca$_{0.5}$MnO$_3$ and Gd$_{0.5}$Ca$_{0.5}$MnO$_3$ manganites is investigated by squid magnetometry. Nd$_{0.5}$Ca$_{0.5}$MnO$_3$ undergoes a charge-ordering transition at $T_{CO}$=245K, and a long range CE-type antiferromagnetic state is established at $T_N$=145K. The dc-magnetization shows a cooling rate dependence below $T_N$, associated with a weak spontaneous moment. The associated excess magnetization is related to uncompensated spins in the CE-type antiferromagnetic structure, and to the presence in this state of fully orbital ordered regions separated by orbital domain walls. The observed cooling rate dependence is interpreted to be a consequence of the rearrangement of the orbital domain state induced by the large structural changes occurring upon cooling.

Arc discharge between two graphite electrodes submerged in different liquid media yields various dimensional nanocarbon structures such as 1D carbon nanotubes and 2D graphene. Single-walled carbon nanohorns (SWNHs) prepared by submerged arc discharge in liquid nitrogen medium are found to have nitrogen impurities. Here, we report the structure and properties of pure and nitrogen-doped SWNHs obtained by submerged arc discharge in a liquid argon medium. The absence of an XPS N 1s signal, which is present in nanohorns obtained in liquid nitrogen, indicate that the nanohorns are free from nitrogen impurities. Raman spectra show a strong defect-induced D band and current–voltage characteristics show a slight nonlinear behavior. N2 adsorption of pure SWNHs shows type-IV isotherms with a surface area of 300 m2 g−1. Adsorption of CO2 and H2 in pure SWNHs has also been measured. Arc discharge in other liquid media such as water, ethanol, dimethylformamide (DMF), n-methyl pyrrolidone (NMP), formamide, benzene, heptane and acetone yields different nanocarbon structures including multi-walled carbon nanotubes (MWNTs), few-layer graphene, carbon onions and carbon nanoparticles.

No abstract is provided for this article.

We report on the evolution of the Raman-active Ag phonon modes in the charge-ordered manganite Pr0.63Ca0.37MnO3 as a function of temperature from 300 K to 25 K. Our studies reveal that the linewidths of the Ag(2) and Ag(4) phonons increase as temperature decreases. This anomalous temperature dependence of phonon lineshapes, seen for the first time in charge-ordered manganites, can be quantitatively understood in terms of a strong spin-phonon coupling involving t2g spins and Ag phonons.

Invited for the cover of this issue is the group of Prof. C.àN.àR. Rao from Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India. The cover image shows the aliovalent substitution of N 3– and F – in place of O 2– in HgO to obtain Hg 2 NF.