Re: Fw: [News-Australia] Super rats high on poison invade Sydney

Potassium cyanide is KCN  In the CN- anion, there is a triple bond between the C and N, and the negative charge is on the C, making it a carbanion. It is isoelectronic with CO, which has a negative charge on the C and positive charge on the O. Both owe their high toxicity through being to preferentially bond through the negatively-charged C atom to the positively-charged Fe atom in hemoglobin, preventing the O2 molecule from bonding and causing death through anoxia.

John W.

--- On Fri, 1/6/12, Marcel Grygo <[email protected]> wrote:
From: Marcel Grygo <[email protected]>
Subject: Re: [The Chemistry Cluster] Fw: [News-Australia] Super rats high on poison invade Sydney
To: "[email protected]" <[email protected]>
Date: Friday, 1, June, 2012, 9:11 AM
















 



  


    
      
      
      thank you,

 

 Do you happeen to know the chemical formula for cyanide? I've been wondering that for some time 

 

thanks,

Marcel 



________________________________

From: John W <[email protected]>

To: [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected]; [email protected] 

Sent: Thursday, May 31, 2012 11:52 AM

Subject: [The Chemistry Cluster] Fw: [News-Australia] Super rats high on poison invade Sydney



  



See the news item below. They are as big as cats, so I heard. And of 

course there are the two-legged rats there, being prolific in a place 

like Sydney.



The usual cumulative poison in modern (from 1948) rat baits, combined 

with an attractant and dyed blue-green to make them less attractive to 

birds, used to be warfarin ((RS)-4-hydroxy- 3-(3- oxo- 1-phenylbutyl)- 2H- chromen- 2-one),

an anti-coagulant (still used medically in small amounts to prevent 

blood clots in thrombosis and phlebitis cases) derived from coumarin, 

until rats resistant to it began to appear; see http://en.wikipedia.org/wiki/Warfarin . Its molecular structure is at http://upload.wikimedia.org/wikipedia/commons/thumb/7/7e/Warfarin.svg/220px-Warfarin.svg.png . 



It is still used for this purpose, although more potent poisons such as brodifacoum , which is now the most common poison used, have since been developed, see http://en.wikipedia.org/wiki/Brodifacoum .

The chemical structure of brodifacoum is similar to that of warfarin, 

except that it has a much larger aromatic side-chain on the 

4-hydroxy-coumarin base structure, and this side-chain also has a 

bromine atom, see http://upload.wikimedia.org/wikipedia/commons/thumb/d/d7/Brodifacoum.svg/200px-Brodifacoum.svg..png

, which makes it extremely toxic and much less biodegradable, although 

less volatile and water-soluble; but at the same time much costlier to 

synthesize than warfarin. As the result of the added bromine atom, 

brodifacoum has an especially long half-life in the body, up to several 

months, requiring prolonged treatment with antidotal vitamin K

for both human and pet poisonings. Secondary poisonings of predators 

that eat several poisoned rat carcases can occur due to 

the extreme persistence of brodifacoum in both target and 

non-target species. It may also be dispersed by insects that feed on 

poisoned bait without harm and retain the poison within their bodies.



But if rats resistant to brodifacoum as well as warfarin also begin 

appearing, as the article below says, what alternative poisons could be 

used?



An obvious choice of another fairly easily-produced synthetic pesticide 

would be "1080", sodium monofluoroacetate, which is used in New Zealand 

against the introduced Australian brushtail opossum, mostly in aerial 

drops in bush areas too remote or rugged for trapping or shooting or use

of instant-kill cyanide paste for recovery of the pelts; see http://en.wikipedia.org/wiki/Sodium_fluoroacetate

. It is easily produced by reacting sodium monochloroacetate with 

potassium fluoride. Fluoroacetate is toxic to all aerobic species and 

highly toxic to mammals and insects, and unlike brodifacoum, very 

water-soluble and much more readily biodegradable. However, 

weight-for-weight, it is about 50 times less toxic than brodifacoum, for

a lethal dose, and some marsupial species from the southwest of West 

Australia are resistant to it. It can also be used against rabbits, 

wildcats, feral dogs, stoats, wild pigs and similar. The effectiveness 

of sodium fluoroacetate as a rodenticide was first reported in 1942; and

the Wikipedia article mentions its use as a rodenticide in Mexico, 

Japan, and Israel, so it could substitute for brodifacoum. It is also 

toxic to insects, but a very low risk to fish and reptiles. Secondary 

poisoning of wildcats and stoats that scavenge poisoned opossum or 

rabbit carcases following 1080 operations is common. New Zealand is the largest 

user of sodium fluoroacetate, mostly by DOC.



Arsenic (see http://en.wikipedia.org/wiki/Arsenic

) used to be used as a cumulative pesticide for all pest species, 

including insects and bacteria, mostly as lead arsenate and the oxide; 

but its limited supply in ores, and now its important uses in 

semiconductors, alloys, and Tanalin wood preservative (copper 

chromate-arsenate), have made it much too valuable for that. It is also 

too slow in its action, and leaves insoluble residues that can never be 

biodegraded.



Strychnine and brucine, alkaloids derived from the seeds of Strychnos 

species (mostly native to Indonesia and Philippines), have long been 

used as rodenticides, being instantly-acting and much more poisonous to 

rats than brodifacoum; see http://en.wikipedia.org/wiki/Strychnine . However, only limited supplies of Strychnos seeds are available, and strychnine/brucine cannot be economically synthesized.



Potassium or sodium cyanide are used in jams or pastes for killing 

opossums in New Zealand, where instant kill is desired for recovery of 

the pelts, and have been used in baits for other pests such as rats and 

insects, being instantly lethal to many species, although they are about

10 times less toxic than brodifacoum. They are fairly readily 

synthesized. However, these cyanides are water-soluble, and liable to be

hydrolyzed in acid conditions to either cyanogen or hydrogen cyanide 

(prussic acid), which being very volatile can kill by inhalation in a 

similar manner to carbon monoxide. Because of this, a licence is 

required to store, handle and use cyanide in New Zealand.



White phosphorus, usually dispersed in a jam or paste, has also been 

used as a pestidide, mainly for opossums, due to to its liver toxicity, 

with about the same lethality as that of brodifacoum. However, it has 

largely gone out of use because it is spontaneously inflammable on 

exposure to air in the absence of liquid; see http://en.wikipedia.org/wiki/White_phosphorus 



John W.



----------------------------------------------------------



http://nz.news.yahoo.com/a/-/mp/13816809/super-rats-high-on-poison-invade-sydney/



Super rats high on poison invade Sydney



Yahoo! New Zealand



May 30, 2012, 2:37 pm



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A new breed of rodents dubbed 'super rats' has overrun one of Australia's biggest cities.

The

Daily Telegraph reports the creatures are too clever to be caught with 

conventional traps and are immune to most commercially-available poison. They

are reportedly also intelligent enough to steal the food out of traps 

without setting them off, making them a big problem across Sydney.

Australian Museum naturalist Martin Robinson told The Daily Telegraph the rats aren't just immune to bait, they thrive on it. "A

lot of suburban rats have been baited for as long as Sydney has been 

settled, so many populations have become immune to those baits.".

According to Robinson, there's only one way to get rid of the creatures which are dirtier than cockroaches.. Bacon

rind or anchovies are attached to the trap and tied down with 

fuse-wire. This ensures the rodents can't escape without springing the 

catch.

Colonies of rats are known to be well-established in Hyde 

Park, but an increases in rat infestations have been reported in 

Cronulla, Brighton Le Sands, Rose Bay, Bellevue Hill, Surry Hills and 

Paddington...

Like most other unwanted visitors, cold weather conditions push rats indoors.



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