Tetraethyltins

The toxicity of the tetraorganotins has beenUtde studied. Available Hterature indicates that tetrabutyltin and the higher tetraalkyltins are substantially less toxic than triorganotins to mammals if taken orally (175). The high toxicity reported for tetraethyltin (LD g = 9 16 mg/kg) appears to be caused by its rapid conversion in the Hver to a triethyl tin species. 

The ether is removed by distillation, and the crude tetra-ethyltin is distilled under water-prunp vacuum, using a water bath for heating. The yield of tetraethyltin boiling at 63-65°/12 mm. is 67-72 g. (89-96%), d 1.4693-1.4699, df 1.1916 (Note 9). 

Tetraethyltin has been prepared from tin-sodium alloy and ethyl iodide, from tin-sodium-zinc alloy and ethyl bromide, and from tin tetrachloride and ethylmagnesium bromide. The method described is essentially that of Pfeiffer and Schnur-mann. ... 

The function of the tetraethyltin is to create vacant sites so that coordination of alkene molecules becomes possible, and to change the oxidation state of the tungsten atom from +6 to +4. Similar behavior of the aluminum compound in the system WCL-CgHsAlCb is not probable, because it has been demonstrated that WCle-AlClg is also an active catalyst (22, 44), which suggests that C2H5AICI2 functions as a Lewis acid. Vacant sites can be created by a Lewis acid as follows ... 

Temperature programming packed-capillary and open capillary HTLC-ICP-MS (up to 200 °C) has been reported [738]. //.HTLC-ICP-MS instrumental coupling has been applied to organotin (tetraethyltin, tributyltin chloride and triphenyltin chloride) and organolead (tetramethyllead and tetraethyllead) compounds [756]. HTLC-ICP-MS can be used for the determination of organometallic compounds at low concentrations. The observed limit of detection (LOD) was 5pg for Pb in... 

Helium MIP-MS is also a very sensitive detection system for organotin compounds, such as tetraethyltin (TET), tetrabutyltin (TBT), triethyltin bromide (TET-Br), tripropyltin chloride (TPT-C1), tributyltin chloride (TBT-C1), and others, separated by CGC [213]. Detection limits at sub-pg levels were achieved, and linear dynamic ranges of at least three orders of magnitude were obtained. 

Tetraethyltin ZDDP, ZDTP Zinc dialkyl dithiophosphates... 

The surface reaction of the chemisorbed hydrogen and tetraethyltin (a controlled surface reaction) was used to produce bimetallic surface species with direct Sn-Pt interaction, which were decomposed in a hydrogen atmosphere in a subsequent step (Scheme 7.21).308... 

Disproportionation to form tetraethyltin was observed when triethyltin cyanoacetate was heated (50). The fate of the cyanoacetate group was not established. 

In 1954, a proprietary formulation, Stalinon , was marketed in France for oral administration of boils. The formulation was primarily linoleic acid but was contaminated with triethyltin (TET)iodide (LD50 in rats, ca 0.7 mg/kg1) and may have contained the mono-, di- and tetraethyltin compounds. The formulation led to the death of 102 people and the intoxication of more than 200 others. The TET caused altopic cerebral edema of the white matter of the brain. Since the Stalinon Affair , a great deal of control has been exerted in the manufacture and marketing of organotins and few deaths have occurred11. The accidental exposure of six industrial workers to TMT led to one death and to two seriously... 

As mentioned before, the diethyl-, triethyl- and tetraethyltin compounds were dealky-lated to give rise to ethylene as a major product and ethane as a minor product with liver microsomal fractions, NADH and oxygen27. Tetraethyltin was found to be converted into triethyltin salts in significant concentrations. 

Domestic chicken Daily doses >0.0001 mg tetraethyltin/kg BW produced adverse effects on... 

The Stille coupling of tetraethyltin and chloropyrazine 15 led to ethylpyrazine 16, which was an important intermediate for preparing quinuclidinylpyrazine derivatives as muscarinic agonists [13]. In this particular case, the reductive elimination took place faster than (3-hydride elimination. 

---