Some silicon-nitrogen compounds

We mention here a few compounds which present points of particular interest. The planarity of N(SiH3)3 has been noted coplanar N bonds are also formed in the cyclodisilazane (a). More complex Si—N ring systems include the cyclotetra-silazane (b), which is of interest because both chair and cradle forms of the 

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Some sulphinyl chlorides have been shown95 to react with silicon-nitrogen compounds or amines to give the sulphinamides (16) and (17). The compounds are reactive intermediates, reacting with trichloromethanesulphenyl chloride and PC15 to form (18) and (19). Compound (19) is cleaved by thermolysis to form sulphinyl chlorides and the trimeric phosphonitrile... 

Because of the wide spectrum of activity shown by amines, definitive conclusions concerning structure-activity relationships cannot be made at this time. However, studies using single test systems reveal that the most active silylated amines contain the silicon atom in a y position relative to the nitrogen, as shown in partial structures 12 and 13 (55, 56). Some examples of compounds containing these groupings are found in Tables I and II. The silylated benzhydryl ethers (Section II,F) and sila-tranes (Section III,C) also contain this type of grouping. 

The most widely used in foam control are special materials called antifoams. They could be fats, oils, waxes, fatty alcohols and acids, ethers, organic compounds containing nitrogen and sulphur (alkylamines and amides, sulphides, thioethers, etc.), phosphorus organic compounds (in particular, tributylphosphate), silicon-organic compounds (silicon oils) and some non-ionic surfactants [e.g. 4,5]. 

In Table 1 the structural data of the synthesized intramolecularly donor-stabilized silenes 10,11, 14 and 15 are summarized and additionally, for comparison, some data taken from the literature are given. The silicon-carbon distances, the silicon-nitrogen distances and the sums of angles at the silene silicon atoms as well as at the silene carbon atoms of the unsaturated siUcon compounds... 

There are reported numerous examples of the syntheses of dihalocyclo-propanes via addition of PTC-generated dihalocarbenes to unsaturated compounds such as alkenes, unconjugated and conjugated di- and polyenes, allenes, cumulenes functionalized alkenes such as haloalkenes unsaturated ethers, acetals, and ketals esters of imsaturated alcohols alkenes substituted by sulfur, nitrogen, silicon atoms some unsaturated carbonyl compounds, etc (eqs. 108-114). 

The metal reacts with halogens above 200°C forming its trihalides. It combines with nitrogen above 1,000°C producing a nitride, YN. It combines at elevated temperatures forming binary compounds with most nonmetals and some metalloid elements such as hydrogen, sulfur, carbon, phosphorus, silicon, and selenium. 

The evolution of a lake or pond into dry land depends on the presence of nutrients in the water. The term nutrients refers to elements and compounds that are necessary for the growth of plants. Nutrients are commonly divided into two categories major nutrients and minor nutrients, also known as micronutrients. Despite some differences in the way that various elements and compounds are classified, carbon, nitrogen, and phosphorus are always regarded as major nutrients. Some authorities also list potassium, sulfur, calcium, magnesium, and/or iron as major nutrients. Micronutrients include aluminum, boron, chlorine, copper, manganese, molybdenum, silicon, and zinc. 

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