Mercury alkyls molecule

Work on mercury alkyls has been done by Heitz and Adloff (31-33), who studied Hg(CH3)2, Hg(C2Hj)2 and HgPh2. They found no isotope effect between " Hg, Hg, and ° Hg, and no correlation with the respective conversion coefficients. They also noted that the retentions could not be satisfactorily explained by exchange of the respective ligands, and thus concluded that the molecules are reformed by an epithermal not by a thermal process. Parent yields were typically 74, 15, and 8% for the diphenyl-, dimethyl- and diethylmercury, respectively. 

To perform the dissociation of the hydrocarbon to alkyl radicals with C—C bond scission, a hydrocarbon molecule should absorb light with the wavelength 270-370 nm. However, alkanes do not absorb light with such wavelength. Therefore, photosensitizers are used for free radical initiation in hydrocarbons. Mercury vapor has been used as a sensitizer for the generation of free radicals in the oxidized hydrocarbon [206-212], Nalbandyan [212-214] was the first to study the photooxidation of methane, ethane, and propane using Hg vapor as photosensitizer. Hydroperoxide was isolated as the product of propane oxidation at room temperature. The quantum yield of hydroperoxide was found to be >2, that is, oxidation occurs with short chains. The following scheme of propane photoxidation was proposed [117] ... 

Treatment of the mercurio ketone with Ni(CO)4 results in a symmetrical coupling with incorporation of one molecule of carbon monoxide to give a triketone presumably via a 3-nickel substituted ketone Eq. (28) [34], This symmetrical coupling reaction is general for alkyl mercury compounds. 

Both halves of a diaryl ditellurium molecule are transformed into aryl alkyl tellurium compounds in reactions with dialkyl mercury compounds1 2. Diphenyl mercury did not react1. 

The base-catalyzed conversion of 5-alkyl-substituted isothiazolium salts 88 (R = Me, R = Et) to 2,3-dihydrothio-phene derivatives 329 occurs in basic conditions via intermediates 328. The distribution of diastereomers 329 is dependent on the base and aryl substituent <1997SUL35>. Similar behavior was observed in the case of 88 (R = R =-(0112)4-) <1996JPG424>. The condensation of 5-Me-substituted isothiazolium salts 88 with a second molecule of a different isothiazolium salts affords haA -thia-Eh-diazapentalenes 330. In this way, macrocyclic ethers 332 were prepared from 331 and their complexation behavior toward sodium(l), silver(l), and mercury(n) studied <2001PS(170)29>. 

In its covalent compounds thallium shows no reluctance to utilizing the two 6s electrons for bond formation. Indeed monoalkyl derivatives Tl(Alk) in which the valence group would be (2, 2) are not known, whereas trialkyls (valence group 6) are known and the most stable alkyl derivatives are the dialkyl halides such as [T1(CH3)2]I. These are ionic compounds-[T1(CH3)2] OH being a strong base—and in the Tl(Alk)2 ions the thallium atom has the same outer electronic structure as mercury in CH3-Hg-CH3, viz. (4). Accordingly the (CH3-T1-CH3) ion is linear, as shown by the determination of the crystal structure of Tl(CH3)2l. In molecules such as Tl(Alk)2A, where A represents a molecule of a /3-diketone, T1 apparently has the valence group (8). 

Alkyl hypochlorites and hypobromites are relatively stable molecules alkyl hypoiodites can only be prepared in situ, usually by the reaction of alcohols with metal acetates or oxides and iodine or by the reaction of alcohols with a hypervalent iodine compound and iodine.1319 Alkyl hypochlorites and hypoiodites can be utilized in reactions that parallel those of the organic nitrites (Barton reaction Section 6.4.2). For example, the photochemistry of the steroidal hypoiodite 497, prepared by the reaction of the corresponding alcohol with iodine oxide (I2O) generated from mercury(II) oxide and molecular iodine in situ, affords a new five-membered ring via an O I bond fission, 1,5-hydrogen abstraction and substitution (Scheme 6.244).1353... 

Their positions in the primary structure have been determined as Cys-46 and Cys-174, respectively (Section II,B). Reactive cysteine residues have also been alkylated with iodoacetamide iHO), modified with spin-labeled reagents HI) and with a mercury substituted salicylate molecule 107). In the latter case the X-ray analysis has shown that two molecules are bound to Cys-132 and Cys-240, respectively. In the homologous rat enzyme other cysteine residues, now known to be ligands to the second zinc atom (Section II,C,3,b), have been differentially carboxymethylated 52). 

In contrast, alkyl and aryl mercury halides (and numerous other derivatives in which X is a relatively electronegative group other than halogen) have been known for a long time, and are monomeric linear molecules. 

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