phthalic ester An ester of phthalic
acid. Phthalic esters are made by reacting phthalic anhydride with an alcohol in the presence of sulphuric
acid. They are high boiling-point liquids used as plasticizers and in the
manufacture of polymers and alkyd
resins. The dimethyl ester is used as
an insect repellent.
phthalocyanine A synthetic compound having molecules with four
isoindole rings linked by –N= bridges.
The structure is similar to that of the
*porphyrins. It can form complexes
with central metal ions. Copper
phthalocyanines are used as dyes.
physical chemistry The branch of
chemistry concerned with the effect
of chemical structure on physical
properties. It includes chemical thermodynamics and electrochemistry.
physisorption See adsorption.
phytostigmine See eserine.
pi-adduct An adduct that is formed
by donation of an electron pair between a pi orbital and a sigma or pi
orbital.
piano stool See sandwich compound.
pi bond See orbital.
pico- Symbol p. A preÜx used in the
metric system to denote 10
–12
. For example, 10
–12 farad = 1 picofarad (pF).
picrate A salt or ester of picric acid.
picric acid (2,4,6-trinitrophenol) A
yellow highly explosive nitro compound, C 6 H 2 (NO 2 ) 3 ; r.d. 1.8; m.p.
122°C.
pi electron An electron in a pi orbital. See orbital.
pig iron The impure form of iron
produced by a blast furnace, which is
cast into pigs (blocks) for converting
at a later date into cast iron, steel,
etc. The composition depends on the
ores used, the smelting procedure,
and the use to which the pigs will
later be put.
pinacol rearrangement A reaction in which the diol pinacol, (CH3) 2
COH(CH 3 ) 2 COH, converts to the ketone pinacolone, CH 3 COC(CH 3 ) 3 ,
under acid conditions, with loss of a
molecule of water. A methyl group
moves from one carbon atom to an
adjacent one in order to stabilize
an intermediate carbocation. The
reaction, also called the pinacolpinacolone rearrangement, gives its
name to a class of similar rearrangements.
pi orbital See orbital.
419
pi orbital
p
N
N
N
N
NH
N
N
N
H
Phthalocyanine
%
*
%
*
1
*
1*
%*
%*
%
*
%
*
%
*
1
%*
RKPCEQN
RKPCEQNQPG
Pinacol rearrangement
www.AzShimi.ir www.AzShimi.com
acid. Phthalic esters are made by reacting phthalic anhydride with an alcohol in the presence of sulphuric
acid. They are high boiling-point liquids used as plasticizers and in the
manufacture of polymers and alkyd
resins. The dimethyl ester is used as
an insect repellent.
phthalocyanine A synthetic compound having molecules with four
isoindole rings linked by –N= bridges.
The structure is similar to that of the
*porphyrins. It can form complexes
with central metal ions. Copper
phthalocyanines are used as dyes.
physical chemistry The branch of
chemistry concerned with the effect
of chemical structure on physical
properties. It includes chemical thermodynamics and electrochemistry.
physisorption See adsorption.
phytostigmine See eserine.
pi-adduct An adduct that is formed
by donation of an electron pair between a pi orbital and a sigma or pi
orbital.
piano stool See sandwich compound.
pi bond See orbital.
pico- Symbol p. A preÜx used in the
metric system to denote 10
–12
. For example, 10
–12 farad = 1 picofarad (pF).
picrate A salt or ester of picric acid.
picric acid (2,4,6-trinitrophenol) A
yellow highly explosive nitro compound, C 6 H 2 (NO 2 ) 3 ; r.d. 1.8; m.p.
122°C.
pi electron An electron in a pi orbital. See orbital.
pig iron The impure form of iron
produced by a blast furnace, which is
cast into pigs (blocks) for converting
at a later date into cast iron, steel,
etc. The composition depends on the
ores used, the smelting procedure,
and the use to which the pigs will
later be put.
pinacol rearrangement A reaction in which the diol pinacol, (CH3) 2
COH(CH 3 ) 2 COH, converts to the ketone pinacolone, CH 3 COC(CH 3 ) 3 ,
under acid conditions, with loss of a
molecule of water. A methyl group
moves from one carbon atom to an
adjacent one in order to stabilize
an intermediate carbocation. The
reaction, also called the pinacolpinacolone rearrangement, gives its
name to a class of similar rearrangements.
pi orbital See orbital.
419
pi orbital
p
N
N
N
N
NH
N
N
N
H
Phthalocyanine
%
*
%
*
1
*
1*
%*
%*
%
*
%
*
%
*
1
%*
RKPCEQN
RKPCEQNQPG
Pinacol rearrangement
www.AzShimi.ir www.AzShimi.com