A Department Of Chemistry

The effects of selected preparative variables on the performance of Cu/Co/Al/Zn catalysts during the conversion of synthesis gas (CO/H 2 ) to higher alcohols, C 2 –C 6 , have been investigated. A series of Cu/Co/Al/Zn catalysts with fixed composition have been prepared ...

The oxidation of alcohols with tert-butylhydroperoxide (TBHP), in the presence of immobilized Co
2+
complexes with ligands of
2,20-bipyridine (bpy), ethylenediamine (en), acetylacetonate (acac), urea, N,N0-ethylenebis(salicylideneamine) (salen), N,N0-propyl-
enebis(salicylideneamine) (salpn) and N,N0-phenylenebis(salicylideneamine) (salophen) were investigated. It was found that immo-
bilized [Co(bpy) 2 ]
2+
/bentonite is an efficient catalyst for the oxidation of alcohols such as cyclohexanol (91% conversion; 100%
selectivity), benzyl alcohol (53% conversion; 100% selectivity) and hexanol (40% conversion; 100% selectivity). Effect of reaction
time, effect of the amount of Co
2+
in catalyst and the effect of type of substrates and oxidants in this catalysis systems were inves-
tigated. In the best conditions, TBHP is more efficient oxidant with respect to H 2 O 2 and order has been observed for the percentage
of conversions of alcohols: 2
> benzylic > 1
.

The binary phase diagram of medetomidine hydrochloride was determined based on thermogravimetric
differential thermal (TGA/DTA) measurements. The binary phase diagram presented a eutectic point in
the 19:81 [(R)/(S)] composition and the ternary phase diagram in the presence of 2-propanol showed a
eutectic point in the 75:25 [(S)/(R)] composition, both characterizing the product as a racemic compound
forming system. The solubility of enantiomeric mixtures in 2-propanol was measured at 10, 20 and 30 C.
The ideal solubility curves of the mixtures were calculated and the activity coefficients derived. A semi-
empirical thermodynamic model UNIversal QUAsi-Chemical (UNIQUAC) was used to predict the solubil-
ity  of  various  compositions  of  enantiomers  at  different  temperatures.  There  was  good  agreement
between the experimental solubility data of medetomidine hydrochloride and the results obtained from
the UNIQUAC equation.

Medetomidine {4-[l-(2,3-dimethylphenyl)ethyl]-3H-imidazole], 5} is a selective a 2 -adre-
noceptor agonist used in veterinary medicine for its analgesic and sedative properties.
1,2
It  is  also  an  alternative  and  environmentally  acceptable  anti-fouling  biocide  which
impedes the settlement of barnacles at nanomolar concentrations and replaces toxic anti-
fouling coatings based on heavy metals.
3–5
Several syntheses of medetomidine have been
reported.
6–13

The binary phase diagrams of hydrogen halides salts of medetomidine (Med.HX,
X:Br,I)  and  hydrogen  oxalate  salt  of  medetomidine  (Med.Ox)  were  determined  based  on
thermogravimetric/differential thermal analysis (TGA/DTA) and their crystal structure behavior
was con fi rmed by comparison of the X-ray diffractometry and FT-IR spectroscopy of the racemate
and pure enantiomer. All hydrogen halide salts presented racemic compound behavior. Heat of
fusion of halides salt of (rac)-medetomidine decreased with ionic radius increase. Eutectic points
for Med.HCl (previously reported), Med.HBr, and Med.HI rest were unchanged approximately.
The solubility of different enantiomeric mixtures of Med.HBr and Med.HI were measured at 10,
20, and 30°C in 2-propanol showing a solubility increase with ionic radius. A binary phase diagram
of Med.Ox shows a racemic conglomerate behavior. The solubility of enantiomeric mixtures of
Med.Ox were measured at 10, 20, 30, and 40°C. The ternary phase diagram of Med.Ox in ethanol
conforms to a conglomerate crystal forming system, favoring its enantiomeric puri fi cation by prefer-
ential crystallization. Chirality 26:183–188, 2014.

Chloroplatinic  ions are  reduced  by hydrogen  preadsorbed  on the metallic  particles
of an alumina-supported  platinum  catalyst.  This  reduction  induces  a uniform  growth
of the  particles.  The transformation  in the catalyst  was  followed  by H2-02  titrat-
ions and  T.E.M.

A  large  library  of  pyrano[2,3-d]pyrimidines  and  pyrido[2,3-d]pyrimi-
dines was synthesized through the reaction between various aromatic aldehydes,
malononitrile  and  pyrimidine  derivatives  in  the  presence  of  Al-HMS-20  as  the
catalyst in EtOH at room temperature after 12 h. This multi-component approach is
a very efficient and economical benign process.

Pulse

current

deposition

was

applied

for

the

first

time

in

the

cathodic

electrodeposition

of

cobalt

hydrox-
ide

from

nitrate

bath

and

ultrafine

nanoparticles

of

-Co(OH) 2 were

prepared

via

this

route.

The

crystal
structure

and

morphology

of

the

prepared

Co(OH) 2 were

analyzed

by

X-ray

diffraction

spectroscopy,
scanning

and

transmission

electron

microscopes.

The

XRD

analysis

revealed

that

the

deposited

hydrox-
ide

has

a

pure

brucite-like

phase

of

Co(OH) 2 .

Morphological

characterization

by

SEM

and

TEM

revealed
that

the

prepared

-Co(OH) 2 is

composed

of

well-dispersed

ultrafine

particles

with

size

of

about

5

nm.
The

energy

storage

ability

of

the

prepared

nanoparticles

was

studied

by

means

of

cyclic

voltammetry

(CV)
and

galvanostatic

charge–discharge

tests

in

1

M

KOH.

The

nanoparticles

showed

an

excellent

energy

stor-
age

ability,

where

they

delivered

an

energy

density

of

0.105

Wh/g

with

coulombic

efficiency

of

91.8%.
Result

of

this

work

showed

that

pulse

current

cathodic

electrodeposition

can

be

recognized

as

a

facile
route

for

the

preparation

of

very

fine

nanoparticles

of

cobalt

hydroxide.