"If any one answer me I will mark him brainiest answer" which substance was discovered by originator of chemical industry in india, prafull chandra roy .
Answers
Prafulla Chandra Ray was the pathfinder and originator of chemical research in modern India. He was introduced to re- search by Alexander Crum Brown, a notable chemist and teacher at Edinburgh University. His doctoral work was on the chemis- try of double sulphates.
Mercurous Nitrite and Related Compounds
In 1895 Prafulla Chandra reported the first synthesis of the
hitherto unknown mercurous nitrite, HgzCN02)Z- This event
was described by him in his autobiography as "the discovery of
mercurous nitrite opened a new chapter in my life". It is relevant
to mention here that stable mercury(I) complexes are sparse in
literature, even today, owing to the instability of mercury(I)
towards disproportionation to mercury(II) and metallic mer-
cury in solution. Moreover, the nitrite ion is not very stable and
can undergo facile decomposition. The compound, HgzCN02)2 is
thus a fascinating example of a stable substance composed of two
relatively unstable ions.
The preparation of Hg2
(NO)2 was an accidental discovery. He
wanted to prepare water soluble mercurous nitrate as an inter-
mediate for the synthesis of calomel, Hg2
C12. Accordingly, di-
lute aqueous nitric acid (1 :4) was reacted with excess mercury.
To his surprise this resulted in the formation of yellow crystal-
line HgzCN02)2'
Hg (excess) + HN03 (dilute) (1)
This result was first published in the Journal of Asiatic Society of
Bengal which was immediately noticed by Nature. This was the
beginning of a series of thorough investigations which resulted
in many significant publications on this nitrite and its deriva-
tives.
It is now known that the nitrite ion can bind to a metal ion in
three different fashions (Figure 1) and there have been numerous
structural investigations in many laboratories around the world
to sort out the coordination modes. As mercury (Figure la) is a
soft cation, the nitrite ions in HgzCN02)2 are likely to be linked
to mercury (Figure la), which exist as a dimer due to metal-metal
bonding, through the soft nitrogen centers forming a linear N-
Box 1. Categories
of Research
Contributions
(i) Metal nitrites with
special reference to mer-
curous nitrite
(ii) Ammonium nitrite
and related compounds
(iii) Chemistry of sulphur
compounds
(iv) Coordination com-
pounds
Figure 1. Coordination
modes of N02
- to metal.
~ .t-M
o . (a)
(b)
-O-M .-1 O~N (c)
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