Synthesis and Characterisation of Cobalt(II) Complexes of 3-Hydroxyflavone

The syn theses of diaquabis (3-hydroxyflavonato) cobalt(II) and bis(pyridine) bis (3hydroxyflavonato) cobalt(II) are described. Results from infrared spectra clearly show that the 3-hydroxyflavonato anion forms a chelate through the 3-hydroxy 4-keto groups. The electronic spectra of both complexes indicate that cobalt(II) has an octahedral geometry. Quantitative analyses of the isolated products gave good agreement with calculated values. Magnetic moment measurements show that both compounds are high spin £ cobalt(II) complexes. The powder diffraction pattern of the pyridine adduct gave almost 1:1 correspondence with tTans-bis (pyridine) bis (3-hydroxyflavonato) nickel (II) which has an octahedral geometry. Therefore, it is highly likely that bis(pyridine)bis(3hydroxyflavonato) cobalt(II) is octahedrally co-ordinated with two chelating 3-hydroxyflavonato anions and two pyridine molecules occupying tTans positions

A new critical curve for a class of quasilinear elliptic systems

We study a class of systems of quasilinear differential inequalities associated to weakly coercive differential operators and power reaction terms. The main model cases are given by the $p$-Laplacian operator as well as the mean curvature operator in non parametric form. We prove that if the exponents lie under a certain curve, then the system has only the trivial solution. These results hold without any restriction provided the possible solutions are more regular. The underlying framework is the classical Euclidean case as well as the Carnot groups setting.Comment: 28 page

Bis(N-isopropyl-N-methyl­dithio­carbamato-κ2 S,S′)diphenyl­tin(IV)

The dithio­carbamate anions in the title compound, [Sn(C6H5)2(C5H10NS2)2], chelate to the SnIV atom, which is six-coordinated in a skew-trapezoidal-bipyramidal geometry. The mol­ecule lies across a twofold rotation axis

Synthesis and Characterization of Dibutyltin(IV) Comp)exes of Substituted Catechol

The complexes of dibutyltin (IV) with anions of 4-tert-buty1catechol, 4chlorocatechol, 4-nitrocatechol, 3,4-dihydroxybenzaldehyde, and 3,4dihydroxybenzoic acid were synthesized by reacting dibutyltin (IV) oxide with the corresponding free ligands. The isolated complexes were characterized by elemental analysis and spectroscopic methods such as infrared, lH and 13C NMR. Complex formation between the dibutyltin(IV) moiety and the anions of 4-tert-butylcatechol, 4-chlorocatechol, 4-nitrocatechol and 3,4dihydroxybenzaldehyde takes place with chelation at the o-hydroxy positions. However, results of analysis carried out on the dibutyltin (IV) complex of 3,4dihydroxybenzoic acid showed that the carboxylic group is also involved in chelate formation. Results of the lethality bioassay on the brine hrimp (Artemia salina) indicated that all the complexes have biological activity but only the 4tert- buty1catechol complex was able to cleave D A (plasmid pBR 322)

Geodesic Motions in 2+1 Dimensional Charged Black Holes

We study the geodesic motions of a test particle around 2+1 dimensional charged black holes. We obtain a class of exact geodesic motions for the massless test particle when the ratio of its energy and angular momentum is given by square root of cosmological constant. The other geodesic motions for both massless and massive test particles are analyzed by use of numerical method.Comment: 13page

3-(2-Hy­droxy­phen­yl)-1-{(E)-[1-(pyrazin-2-yl)ethyl­idene]amino}­thio­urea monohydrate

In the title compound, C13H13N5OS·H2O, the thio­urea mol­ecules closely resemble each other and are approximately planar; the dihedral angles formed between the terminal benzene rings are 7.88 (8) and 7.20 (8)°, respectively. The observed planarity correlates with the presence of bifurcated N—H⋯(O,N) hydrogen bonds. In the crystal, the mol­ecules are connected into supra­molecular double chains via a combination of N—H⋯S (linking the two independent mol­ecules), O—H⋯O and O—H⋯N (linking dimeric aggregates into a supra­molecular chain via hy­droxy–water, water–water and water–pyrazine inter­actions) and O—H⋯S hydrogen bonds (connecting two chains). The chains are further connected by C—H⋯N and C—H⋯S inter­actions

n-Butyl­dichlorido{4-cyclo­hexyl-1-[phenyl(2-pyridyl-κN)methyl­ene]­thiosemicarbazidato-κ2 N 1,S}tin(IV) chloro­form monosolvate

The monodeprotonated Schiff base ligand in the title com­pound, [Sn(C4H9)(C19H21N4S)Cl2]·CHCl3, N,N′,S-chelates to the Sn atom, which is six-coordinated in an octa­hedral environment. The three coordinating atoms along with the butyl C atom comprise a square plane, above and below which are positioned the Cl atoms. The amino group is a hydrogen-bond donor to a Cl atom of an adjacent mol­ecule, the hydrogen bond giving rise to a helical chain propagating in [010]. The Cl and H atoms of the chloro­form mol­ecule are disordered over two positions in an 0.67:0.33 ratio

Internationalisation of Malaysian universities: a case study of the National University of Malaysia / Norzaini Azman and Yang Farina Abd. Aziz

The Malaysian government aspires to be the educational centre for excellence in the Asian region. Strategies for internationalisation are central to the scope the Ministry of Higher Education has taken and the goals it has set for the future. This article examines how Universiti Kebangsaan Malaysia (National University of Malaysia) is responding to the internationalisation phenomenon. This paper begins by outlining the rationale for internationalisation strategies and their potential consequences for Malaysian universities in order to set the context for discussion. Using Universiti Kebangsaan Malaysia (UKM) as a case study, this article examines activities involved in the pursuit of internationalisation. The emphasis is on what has been done and achieved thus far by UKM to reflect its image as “the National University with an international reach”. A discussion of UKM’s experience in internationalisation practices will, it is hoped, shed light on the general current state of internationalisation in the Malaysian Public higher education system

Chemistry Outreach Program and its Impact on Secondary School Students

AbstractChemistry is one of the most difficult subjects and usually feared by the students in elementary schools. Some of the students in Malaysia, especially in the rural area, they memorized experiments and the theories without really understand the beauty of chemistry. They also believed that the chemistry experiment can only be done in the laboratory equipped with a huge fume hood since all of the experiments are dangerous, explosive and costly. Chemistry outreach program held by a team from Universiti Kebangsaan Malaysia was meant to change the perspective of the elementary students towards chemistry and to develop their interest in exploring the beauty of chemistry. The program took place in Perlis as part of the Science on Wheels Program organized by National Science Centre. Few experiments using chemicals which can be found in daily life were first demonstrated and explained. Then the students were given chances to try on their own. They were also asked to relate what they had learned from the experiments to the phenomenon that occurred in the world. Survey on knowing their interest in chemistry before and after the experiments was given and analyzed. The results showed that the level of liking chemistry and choosing chemistry as one of the career option depended mainly on the exposure towards chemistry. The result showed that 80% of the students were interested in chemistry after they performed the experiments compared to 72% who were interested in the chemistry subject taught in school prior to the experiment. The 8% increment was possibly a reflection of the effective learning through experiment. Overall, 58% of students were interested to choose chemistry as their future career and suprisingly it was not depended on the background of the family. The chemistry outreach program really gave the impact on the elementary students and reached their hearts and should be continued from time to time to attract students to science and technology

SORAS : Additive for arsenic removal from underground water

A quick and easy way has been developed to remove arsenic specifically from aqueous solution SORAS. We have designed and synthesized with high loading capacity properties capable of ensuring safe drinking water containing less than 10 ppb arsenic. We employ the bulk polymerization approach with allylthiourea (AT) as monomer and arsenic (As) as template,in synthetizing the IIP. During the leaching process, the template was removed by acidification