Showing papers on "Organomercury Compounds published in 2012"

Radical Activation of SiH Bonds by Organozinc and Silylzinc Reagents: Synthesis of Geminal Dizinciosilanes and Zinciolithiosilanes**

Abstract: Organozinc compounds are very useful reagents in synthesis, and in analogy to organomagnesium and organolithium compounds are used mainly as nucleophiles. Some reports are also available for silylzinc compounds. At the same time, as Zn and Hg are both Group 12 elements, organozinc compounds are expected also to exhibit some of the characteristic reactions of organomercury compounds. For example, organomercury and silylmercury compounds undergo radical reactions both thermally and photochemically and activate Si H bonds, leading to silylmercury compounds. Such compounds are also excellent precursors for the preparation of silyl anions by transmetalation. The possibility to replace in these reactions the highly toxic organomercury compounds by the less toxic organozinc compounds is attractive. The radical chemistry of organozinc compounds, initiated by dioxygen, is a vigorously developing field of organic chemistry with many applications in synthesis. In contrast, to the best of our knowledge, there are no reports on radical reactions of silylzinc compounds. Activation of Si H bonds is a very useful reaction synthetically and therefore it is intensively studied, both in academia and in industry. There are two common strategies for Si H bond activation: by radical initiators [7] and by transition-metal catalysts. Silylzinc reagents became recently popular synthons in organic chemistry owing to their selective and mild nucleophilic nature. Therefore, a single-pot reaction leading to zinciosilanes by activation of Si H bonds has a great synthetic potential. Furthermore, in analogy to the synthesis of bismercuriosilanes, activation of dihydridosilanes by diorganozinc or disilylzinc compounds can lead, in a single-step reaction, to new geminal dizinciosilanes. These interesting dimetallic reagents are potentially very attractive reagents, in a similar fashion to geminal dizinciomethanes, their organic analogues. Herein, we present the first examples of radical activation of a Si H bond in R3SiH (R=Me3Si, Me3SiMe2Si) and Me3SiMe2SiH by R’2Zn (R’= tBu, Et) and by (tBuMe2Si)2Zn (1) (for experimental details see Supporting Information). Using this reaction we synthesized the silylenoid-type compound [Cl(tBuMe2Si)2Si]2Zn (2), which upon lithiation yields the zinc-bridged bis(silyllithium) [(thf)2Li(tBuMe2Si)2Si]2Zn (3), the first known compound with lithium and zinc bonded to the same Group 14 atom. We have also synthesized and fully characterized the novel tetrametallic bis(zinciosilyllithium)silane [(thf)3Li(tBuMe2Si)2SiZn]2Si(SiMe2tBu)2 (4). The reactions of Et2Zn, which is commercially available, and of tBu2Zn with tBuMe2SiH (5), Me3SiMe2SiH (6), and (Me3Si)3SiH (7) were first studied. The reaction of Et2Zn or of tBu2Zn with 5 was disappointing; 5 remained unchanged after 3 h at 90 8C, even in the presence of azobisisobutyronitrile (AIBN) or tBu2Hg as radical initiators. However, this situation changes upon silyl substitution of the silane. Thus, reaction of Me3SiMe2SiH (6) with tBu2Zn for 3 h at 90 8C yielded (Me3SiMe2Si)2Zn (8) in 30% yield. When a minute amount of tBu2Hg, a radical initiator, was added the yield of 8 increased to 95%. In contrast, 6 was recovered unreacted after reaction with neat Et2Zn and yielded only 10% of 8 in the presence of tBu2Hg at 90 8C for 3 h (Scheme 1).

Synthesis and Electrochemical Behavior of Mixed Organoboron/Organomercury Compounds

Abstract: As part of our ongoing interest in the synthesis and reduction chemistry of organoboron species, we have investigated the synthesis of mixed organoboron/organomercury complexes by reaction of the Li(THF)4 salt of dimesityl-1, 8-naphthalenediylborate with 1, 2-(HgCl)2C6F4 and 1, 3-(HgCl)2C6F4, respectively. The resulting tetranuclear B2Hg2 complexes (2 and 3, respectively) were characterized by multinuclear NMR spectroscopy and single-crystal X-ray analysis. The cyclic voltammogram of complex 2, which features a B–Hg–Hg-B core connected by an ortho-phenylene (Hg–Hg connection) and two peri-naphthalenediyl linkers (B–Hg connection), shows significant coupling of the two electroactive boryl units, presumably via a direct σ interaction of the vacant p orbitals of the four neighboring Lewis acids. This conclusion is supported by DFT calculations, which show that the LUMO of 2 spans the four Lewis acids, with a major in phase contribution from the boron 2p orbitals and the mercury 6p orbitals.

A single crystal X-ray study of the products of halogen mercury cyclization of 8-allylthioquinoline

Abstract: The reaction products of 8-allylthioquinoline with mercury halides are studied by single crystal X-ray diffraction. It is shown that the products are organomercury derivatives of salts of 2,3-dihydro[1,4]-thiazino[2,3,4-ij]quinoliniuim.

Organic Compounds in Soils, Sediments & Sludges: Analysis and Determination

Abstract: Preface 1 Extraction of organic compounds from soil 1.1 Conventional solvent extraction 1.2 Accelerated solvent extraction 1.3 Pressurised liquid extraction 1.4 Microwave-assisted extraction 1.5 Subcritical water extraction 1.6 Solid-phase microextraction 1.7 Supercritical fluid extraction References 2 Organic compounds in soils 2.1 Hydrocarbons 2.1.1 Aliphatic hydrocarbons 2.1.2 Aromatic hydrocarbons 2.1.3 Polycyclic aromatic hydrocarbons (PAH) 2.2 Oxygen containing compounds 2.2.1 Alcohols, ketones and aldehydes 2.2.2 Carboxylic acids 2.2.3 Phenols 2.2.4 Methoxy groups 2.3 Chlorine containing compounds 2.3.1 Chloroaliphatic hydrocarbons 2.3.2 Chloroaromatic hydrocarbons 2.3.3 Chlorophenols 2.3.4 Polychlorobiphenyls 2.4 Nitrogen containing compounds 2.4.1 Aromatic amines 2.4.2 Nitro compounds 2.4.3 N-Oxides 2.4.4 Nitrosamines 2.4.5 Ethylene diamine tetracetric acid 2.4.6 Acrylonitrile 2.4.7 Polycyclic aromatic nitrogen heterocyclic 2.4.8 Miscellaneous 2.5 Sulphur and phosphorus compounds 2.6 Volatile organic compounds 2.7 Polychlorodibenzo-p-dioxins and polychlorodibenzofurans 2.8 Miscellaneous organic compounds 2.8.1 Humic and fulvic acids 2.8.2 Mestranol 2.8.3 Trifluoroacetic acid 2.8.4 Flame retardants 2.8.5 Polystyrene 2.8.6 Further compounds 2.9 Mixtures of organic pollutants in soil 2.9.1 Gas chromatography 2.9.2 Pyrolysis-gas chromatography-mass spectrometry 2.9.3 Purge and trap gas chromatography References 3 Insecticides and herbicides in soils 3.1 Chlorinated insecticides 3.2 Triazine herbicides soil extraction procedures 3.3 Phenoxy acetic acid herbicides 3.4 Carbamate type insecticides 3.5 Substituted urea herbicides 3.6 Imidazolinone herbicide 3.7 Organophosphorus insecticides 3.8 Fungicides 3.9 Miscellaneous insecticides and herbicides 3.10 Multi insecticide/herbicide mixtures References 4 Organometallic compounds in soils 4.1 Organoarsenic compounds 4.2 Organolead compounds 4.3 Organotin compounds 4.4 Organomercury compounds References 5 Extraction of organic compounds from sediments 5.1 Non-saline sediments 5.2 Saline, marine sediments 5.2.1 Filtration methods 5.2.2 Separation by centrifugation 5.2.3 Fractionation methods 5.2.3.1 Fractionation by chemical leaching 5.2.3.2 Fractionation by sedimentation 5.2.4 Other fractionation methods References 6 Organic compounds in non-saline sediments 6.1 Polycyclic aromatic hydrocarbons 6.2 Oxygen containing compounds 6.2.1 Phenols 6.2.2 Carboxylic acids 6.2.3 Aldehydes and ketones 6.2.4 Phthalate esters 6.2.5 Cationic detergent 6.3 Halogen containing compounds 6.3.1 Volatile aliphatic chlorohydrocarbons 6.3.2 Non-volatile aliphatic chlorohydrocarbons 6.3.3 Organohalogen concentration techniques 6.3.4 Chlorinated dioxins 6.4 Nitrogen containing compounds 6.5 Sulphur containing compounds 6.6 Phosphorus containing compounds 6.6.1 Alkyl and aryl phosphates 6.6.2 Inositol phosphate 6.6.3 Adenosine-5'-triphosphate 6.6.4 Nucleotides 6.7 Insecticides and pesticides 6.7.1 Organophosphorus insecticides 6.7.2 Organochlorine insecticides 6.7.3 Azine type herbicides 6.7.4 Carbamate type herbicides 6.7.5 Phenoxy acetic acid type herbicides 6.8 Miscellaneous organic compounds 6.8.1 Humic and fulvic acid 6.8.2 Detergents 6.8.3 Optical whiteners 6.8.4 Carbohydrates 6.8.5 Uronic acids and aldoses 6.8.6 Pharmaceuticals 6.8.7 Sterols 6.8.8 Miscellaneous References 7 Organometallic compounds in non-saline sediments 7.1 Organoarsenic compounds 7.2 Organolead compounds 7.3 Organotin compounds 7.4 Organomercury compounds 7.5 Organosilicon compounds References 8 Organic compounds in saline marine and estuarine sediments 8.1 Marine sediments 8.1.1 Hydrocarbons 8.1.1.1 Aliphatic hydrocarbons 8.1.1.2 Aromatic hydrocarbons 8.1.1.3 Polycyclic aromatic hydrocarbons 8.1.2 Oxygen containing compounds 8.1.2.1 Carbohydrates 8.1.2.2 Surfactants 8.1.3 Halogen containing compounds 8.1.3.1 Chlorophenols 8.1.3.2 Polychlorobiphenyls 8.1.4 Nitrogen containing organic compounds 8.1.5 Sulphur containing organic compounds 8.1.6 Insecticides, pesticides and herbicides 8.1.6.1 Organochlorine insecticides 8.1.6.2 Organophosphorus pesticides 8.1.7 Miscellaneous 8.1.7.1 Priority pollutants 8.1.7.2 Humic and fulvic acids 8.2 Estuary sediments 8.2.1 Chlorobenzenes 8.2.2 Hexachlorophene 8.2.3 Polychlorinated biphenyls, chlorinated insecticides and polycyclicaromatic hydrocarbons 8.2.4 Sterols 8.2.5 Quaternary ammonium compounds 8.3 Lacustrine sediments 8.3.1 Aliphatic hydrocarbons 8.3.2 Polycyclic aromatic hydrocarbons 8.3.3 Sterols 8.3.4 Unsubstituted and hydroxy substituted fatty acids References 9 Organometallic compounds in saline sediments 9.1 Organoarsenic compounds 9.2 Organolead compounds 9.3 Organotin compounds 9.4 Organomercury compounds References 10 Organic compounds in sludges 10.1 Hydrocarbons 10.1.1 Aliphatic hydrocarbons 10.1.2 Polycyclic aromatic hydrocarbons 10.2 Oxygen containing compounds 10.2.1 Alcohols 10.2.2 Aldehydes 10.2.3 Carboxylic acids 10.2.4 Phenols 10.2.5 Surface active agents 10.2.5.1 Anionic types 10.2.5.2 Cationic detergents 10.2.5.3 Non-ionic detergents 10.3 Chlorine containing compounds 10.3.1 Chlorinated hydrocarbons 10.3.2 Haloforms 10.3.3 Chlorophenols 10.3.4 Chlorophenoxyisobutyric acid 10.3.5 Polychloroinated biphenyl 10.3.6 Polychloro-p-benzodioxins and polychlorodibenzofurans 10.4 Nitrogen containing compounds 10.4.1 Nitrilo acetic acid 10.4.2 Ethylene diamine tetracetic acid 10.4.3 Nitrosamines 10.4.4 Guanidines 10.4.5 Miscellaneous nitrogen compounds 10.5 Sulphur containing compounds 10.5.1 Alkyl sulphides 10.5.2 Thiosteroids 10.6 Phosphorus compounds 10.7 Insecticides pesticides herbicides 10.7.1 Organochlorine insecticides 10.7.2 Carbamate insecticides and fungicides 10.7.3 Organophosphorus insecticides 10.7.4 Triazine herbicides 10.7.5 Phenoxy acetic and herbicide 10.7.6 Mirex 10.8 Miscellaneous organic compounds 10.8.1 Cobolamin 10.8.2 Nucleic acids 10.8.3 Adenosine phosphate ether 10.8.4 Humic and fulvic acids 10.8.5 Sucralose 10.8.6 Organic carbon 10.8.7 Miscellaneous 10.9 Mixtures of organic compounds 10.9.1 Gas chromatography 10.9.2 Gas chromatography-mass spectrometry 10.9.3 High performance liquid chromatography 10.9.4 Ion-exchange chromatography 10.9.5 Gel filtration chromatography 10.9.6 Preconcentration References 11 Organometallic compounds in sludges 11.1 Organolead compounds 11.2 Organotin compounds 11.3 Organomercury compounds References Index