Additional hydrocarbon bridges

The dinuclear complex (CpNiCO)2 is a source of NiCp fragments. Their addition to clusters occurs with Os3(CO),2 to form 88 (163) or with the hydrocarbon bridged ruthenium clusters 89 to form 90 (164). The clusters... 

Further approaching and deforming the benzene rings by additional short bridges ought to enhance both of the peculiarities of [2.2]paracyclophane. The recently synthesized highly strained, multiply bridged phane hydrocarbons (e.g. 2,15,16,... 

Beck and co-workers (84,8.5) utilized the anionic carbonylmetallates [M(C0)5] (M = Mn, Re) and [WCp(CO),] in nucleophilic addition reactions with cationic hexadienyl, cyclohexadienyl, cycloheptadienyl, and cyclooctadienyl complexes of iron and ruthenium to give heterobimetal lie complexes with rj iV-hydrocarbon bridges. The reaction of [Fe(i7 -... 

Addition of anionic Fischer carbene complexes, of their CS2 adducts and of an anionic thiocarbyne complex to cationic organometallic Lewis acids and to coordinated, unsaturated hydrocarbons gives novel hydrocarbon bridged heterodimetallic compounds. Oxidative addition of halocarbyne complexes to zerovalent platinum and palladium complexes provides a synthesis of carbido bridged complexes. 

Nucleophilic attack on coordinated unsaturated hydrocarbons is one of the fundamental and particularly well studied reactions in Organometallic Chemistry. The addition of carbonylme-tallates instead of common nucleophiles provides a directed synthesis of hydrocarbon bridged complexes. Carbonylmetallates (particularly Re(CO)5", Os(CO)4 ") add to 7C-bonded olefin, acetylene, allyl, diene, trimethylenemethane, dienyl, benzene, triene and cycloheptatrienyl ligands in cationic complexes and give hydrocarbon bridged bi- and trimetallic, homo- or he-teronuclear complexes [1]. 

Another directed route to hydrocarbon bridged complexes is C-C coupling by addition of anionic 7U-hydrocarbon complexes to coordinated hydrocarbons of cationic complexes [3,4]. 

Aumann has recently studied the addition of the uncoordinated tropylium ion to these anio nic Fischer carbene complexes [9c]. Similarly, the addition of the cationic allyl complex Cp(OC)(ON)Mo(T -C3H5) " gives new hydrocarbon bridged complexes. 

The reaction of the iron-carbene complex [[Bu C CC(OEt)=)Fe(CO)4] with 1,3-cyclohexadiene afforded223 (32), which was characterised by X-ray diffraction. The addition of the anionic derivatives of i-(diphenylmethane)-il-fluorene- and ii-(9,10-dihydroanthracene)-bis tricarbonylchromium to the hydrocarbon moiety (alkene, benzene, cyclohexadienyl, cycloheptadienyl and cycloheptatrienyl) in various cationic compounds of manganese, rhenium, iron, chromium, molybdenum, tungsten and cobalt was reported224 to provide a new route to hydrocarbon-bridged heteronuclear species such as (33). 

R = organic group, R boron substituted organic group, Y = hydrocarbon bridge. Additional metal substituted triorganotin halides are listed in Subsections 2.7 1.1.3 and 2.7.1.2. 

R = hydrogen or an organic group, Y = hydrocarbon bridge, may be functionally substituted. Additional references to diorganotin mercaptides may be found in Chapters 8.1 and 9 ... 

Cyclodienes. These are polychlorinated cycHc hydrocarbons with endomethylene-bridged stmctures, prepared by the Diels-Alder diene reaction. The development of these insecticides resulted from the discovery in 1945 of chlordane, the chlorinated adduct of hexachlorocyclopentadiene and cyclopentadiene (qv). The addition of two Cl atoms across the double bond of the ftve-membered ring forms the two isomers of chlordane [12789-03-6] or l,2,4,5,6,7,8,8-octachloro-2,3,3t ,4,7,7t -hexahydro-4,7-methano-lJT-indene, QL-trans (mp 106.5°C) and pt-tis (32) (mp 104.5°C). The p-isomerhas signiftcantiy greater insecticidal activity. Technical chlordane is an amber Hquid (bp 175°C/267 Pa, vp 1.3 mPa at 25°C) which is soluble in water to about 9 fig/L. It has rat LD qS of 335, 430 (oral) and 840, 690 (dermal) mg/kg. Technical chlordane contains about 60% of the isomers and 10—20% of heptachlor. It has been used extensively as a soil insecticide for termite control and as a household insecticide. 

When rationalizing the significant difference of the hydrocarbon- and ether-bridged radical anions, the main aspect will certainly be the conformation of the oxyethylene chain, which brings the electrophores into closer contact. An additional aspect follows from the ability of the oxygen centres along the chain to chelate the counterion and thus to fix the cation between the electrophores. It is not possible from the available experimental evidence to discriminate between the two effects. The role of ion pairing and the relative position of the counterion and carbanion will be dealt with below. 

Hydrocarbons containing one or more triple bonds in addition to double bonds have been excluded from the tile, as have been radicals (e.g. the allyl radical C3H5 ) and aromatic molecules, i.e. molecules for which more than one unexcited resonance structure (Kekule structure) can be written. Consequently, hydrocarbons such as phenyl-substituted polyenes, or annulenes — bridged or unbridged—have not been included. 

The reagent stoich. fran -Ru(0)3(0Ac)3(py)3/CH3CN oxidised Ph3P to Ph3PO giving what may be Ru" (0)(OAc)(py)3 or a p-oxo bridged polymer. Linear and cyclic alkenes were epoxidised with additional by-products hydrocarbons and... 

Zhang et al. studied the Mn promotion in C0/AI2O3 catalysts.It was found that the addition of Mn improves the catalytic activity, as well as the C5+ selectivity, while the formation of methane and C2 4 hydrocarbons is significantly suppressed. They observed that Mn improved the dispersion of the active Co phase and also favored the formation of bridged-bonded CO as probed with IR. A small amount of Mn was also able to increase the H2 uptake, although it was again decreased with an excess of Mn. 

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