Tartrate-stabilized titanium-oxo clusters containing sulfonate chromophore ligands: Synthesis, crystal structures and photochemical properties

Sn3N4 polymorphs were synthesized via high-pressure nitridation of tin by means of laser-heated diamond anvil cell technique. This implies new insight into the crystal chemistry and functional materials of group IVA nitrides.

Download Full-text

Transferable force field for crystal structure predictions, investigation of performance and exploration of different rescoring strategies using DFT-D methods

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520616006831 ◽

2016 ◽

Vol 72 (4) ◽

pp. 460-476 ◽

Cited By ~ 4

Author(s):

Anders Broo ◽

Sten O. Nilsson Lill

Keyword(s):

Crystal Structure ◽

Force Field ◽

Crystal Structures ◽

Density Functional ◽

Geometry Optimization ◽

Field Methods ◽

Functional Theory ◽

Ranking List ◽

Drug Molecules ◽

New Type

A new force field, here called AZ-FF, aimed at being used for crystal structure predictions, has been developed. The force field is transferable to a new type of chemistry without additional training or modifications. This makes the force field very useful in the prediction of crystal structures of new drug molecules since the time-consuming step of developing a new force field for each new molecule is circumvented. The accuracy of the force field was tested on a set of 40 drug-like molecules and found to be very good where observed crystal structures are found at the top of the ranked list of tentative crystal structures. Re-ranking with dispersion-corrected density functional theory (DFT-D) methods further improves the scoring. After DFT-D geometry optimization the observed crystal structure is found at the leading top of the ranking list. DFT-D methods and force field methods have been evaluated for use in predicting properties such as phase transitions upon heating, mechanical properties or intrinsic crystalline solubility. The utility of using crystal structure predictions and the associated material properties in risk assessment in connection with form selection in the drug development process is discussed.

Download Full-text

An Efficient Simple Hydrothermal Method to Synthesis FeS2 Microspheres and their Optical Property

Materials Science Forum ◽

10.4028/www.scientific.net/msf.847.72 ◽

2016 ◽

Vol 847 ◽

pp. 72-77

Author(s):

Yu Xuan Liang ◽

Peng Peng Bai ◽

Shu Qi Zheng

Keyword(s):

Photoelectron Spectroscopy ◽

Low Cost ◽

Wave Length ◽

Functional Materials ◽

Optical And Electrical Properties ◽

X Ray Diffraction ◽

Synthetic Sample ◽

X Ray ◽

New Type ◽

Good Uniformity

Pyrite (FeS2) is an important semiconductor material which shows various excellent optical and electrical properties and extensive applied prospect as a new-type, photoelectrical functional materials. In this study, a low cost and efficient simple hydrothermal two-step synthetic method was given to obtain FeS2 microspheres with 2-3 μm in diameter. The obtained products were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet and visible spectrophotometer (UV-Vis). XRD showed that the synthetic sample consisted of two crystal structures of FeS2, pyrite and marcasite. SEM observation indicated that FeS2 microspheres were well crystallized and had good uniformity. UV-Vis spectrum had a strong optical absorption in the region of 200-400 nm wave length. The reaction temperature had an impact on the size of FeS2 microspheres. A possible mechanism for the size of the FeS2 microspheres generated at high temperature is smaller than that at low temperature is discussed.

Download Full-text

Photophysical and photochemical properties of electronically excited fluorescent dyes: a new type of time-resolved laser-scanning spectroscopy

International Journal of Photoenergy ◽

10.1155/s1110662x9900029x ◽

1999 ◽

Vol 1 (3) ◽

pp. 165-172 ◽

Cited By ~ 10

Author(s):

Ma. Heupel ◽

I. Gregor ◽

St. Becker ◽

E. Thiel

Keyword(s):

Molecular Oxygen ◽

Laser Scanning ◽

Fluorescent Dyes ◽

High Sensitivity ◽

Ambient Conditions ◽

Time Resolved ◽

Electronically Excited ◽

New Type ◽

Photochemical Properties ◽

Scanning Spectroscopy

The capacity of a new type of time-resolved laser-scanning spectroscopy is discussed. Due to the developed modulation technique we obtain a high sensitivity in the absorption measurement as well as a very efficient suppression of the background absorption. The new technique has been used to investigate photophysical and photochemical properties of fluorescent dyes. All presented results are discussed in view of potential applications like dye laser and fluorescence labelling.The possibility of intermolecular triplet state quenching by molecular oxygen and further agents is considered in detail. The quenching process is described in terms of diffusion controlled interaction. It is shown that under ambient conditions quenching agents can inhibit the quenching by molecular oxygen and therefore the generation of the chemically highly reactive singlet molecular oxygen. It can be expected that the obtained information can be used in order to increase the photostability not only of rhodamine dyes.

Download Full-text

A New Type Electrohydraulic Servo Valve Based on Magnetic Shape Memory Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.873.91 ◽

2013 ◽

Vol 873 ◽

pp. 91-94

Author(s):

Fu Quan Tu ◽

Yang Mao ◽

Ren Bo Xu

Keyword(s):

Magnetic Field ◽

Shape Memory ◽

Functional Materials ◽

Shape Variation ◽

Magnetic Shape Memory ◽

Servo Valve ◽

Magnetic Shape Memory Alloy ◽

New Type ◽

Variation Mechanism ◽

The Relationship

In this paper, the magnetically controlled characteristic and shape variation mechanism magnetic shape memory alloys (MSMA) sample are studied through the servo valve actuator based on the MSMA. The MSMA is a new type of functional materials, which has huge driving force and large controllability displacement. The kind of actuator is designed by differential mode of MSMA, employing bias coils to generate biasing magnetic field and applying field coils to provide magnetic field which is controllable. The relationship between displacement of the new actuator and time is got by numerical simulation using Maxwell software. Finally, motivated by the simulation results, the rationality of structural design of the new type of actuator is validated.

Download Full-text