Potassium, reduction

In an attempt to approach a measure of tt-bonding in the Al-Al bond Uhl et al. examined the alkali metal reduction of tetrakis[bis(trimethylsilyl)methyl]dialane. Sodium or potassium reduction of [(Me3Si)2HC]2Al—Al[CH(SiMe3)2]2 in di-methoxyethane (DME) produced dark blue radical monoanions of [(Me3Si)2 HC]2A1—Al[CH(SiMe3)2]2 (Eq. 2).6... 

Detailed investigations of the chemical reactivity of the diketiminato-stabilized phosphenium cations like 28 (Scheme 17) are to date rare and include only two reports dealing with the substitution and reduction of P-halogen-derivatives. Thus, reaction of 28 (X=Br) with sodium hydroxide in toluene was reported to proceed with displacement of the halide substituent at phosphorus and conservation of the heterocyclic ring to give a mixture of bromide and triflate salts containing a P-hydroxy-substituted cation, both of which were isolated in small yields [89], The products are remarkable as they represent one of very few examples of a stable phosphinous acid which does not rearrange to the tautomeric secondary phosphine oxide. Potassium reduction of the P-chloro-substituted derivative 34 produced the... 

The ESR spectrum of 5,5,10,10-tetramethyl-5,10-dihydrosilanthrene radical anion (VIII R = Me) produced by potassium reduction in DME... 

A triplet dianion of l,3,5-tris(dicyanovinyl)-substituted benzene can be produced by potassium reduction.38 Simulation of the EPR spectrum gave D = 0.0102 cm-1 from which a point dipole distance of 6.4 A was calculated. 

Active zinc prepared from the potassium reduction of zinc chloride... 

Synthesis of 1-alkyl-l-hydropyridinyls is by reduction of the corresponding pyridinium ion. On a preparative scale this has been effected using either zinc or sodium amalgam, with acetonitrile as solvent, in stringently oxygen-free conditions.222-224 For ESR measurements, zinc or potassium reduction in a range of solvents has been used treatment merely by base in an alcohol or dimethyl sulfoxide is also often effective.208 (The mechanism of reduction of this type of system has been discussed.143) Photoreduction has also been used.209... 

Substituted compounds of chromium in negative oxidation states are also known. Two apparent examples are [(77 -C6H6)Cr(CO)3]2- and [(bipy)Cr(CO)4] An EPR spectrum of the latter compound, however, indicated that the unpaired electron resides within the aromatic ring this result implies that chromium is actually in the zero oxidation state, bound to (bipy) . Finally, potassium reduction of Cx r] -Ce )i yielded the corresponding radical anion [Cr(r] -C6H6)2] , a Cr(-I) compound without any carbonyl hgands, which was characterized by ESR spectroscopy. ... 

SiMe3)2CH]2Al-Al[CH(SiMe3)2]2- This compound was prepared by the potassium reduction of bis[bis(trimethylsilyl) methyl]almninum chloride (equation 1). ... 

In an attempt to approach a measure of r-bonding between two aluminum atoms, Uhl etal. examined the alkali metal reduction of [(SiMe3)2CH]2 Al-Al[CH(SiMe3)2]2 Specifically, sodium or potassium reduction of [(SiMe3)2 CH]2Al-Al[CH(SiMe3)2]2 in dimethoxyethane (DME) afforded dark blue colored crystals of the [(SiMe3)2CH]2Al-Al[CH(SiMe3)2]2 radical anion (equation 2) ... 

Although deprotonation of NHC salts have proven to be an efficient synthetic route, the basic reaction conditions can prove incompatible with certain complex synthesis in a one-pot procedure. Thus, other synthetic strategies to generate free carbene have been developed. Khun reported the synthesis of imidazol-2-ylidenes bearing a small alkyl group on the NHC backbone by potassium reduction of the corresponding thiones (10) (equation 5). This method has also been applied in the synthesis of benzimidazole derivatives, by reduction of the corresponding sulfones with Na/K alloy at room temperature. Synthesis of unsymmetrically substituted... 

Adam and Kepford, confirmed by deuteration experiments and obtained by potassium reduction in DME the early literature contained a mis-assignment. Bard and co-workers have correlated homogeneous electron-transfer rates between 107 and its parent heterocycle with heterogeneous rate constants for electroreduction of the heterocycle/ and Japanese workers have described optical absorption spectra for 107 and analogs. They conclude that the heteroatom lias minimal perturbing effect on the 7c-elec-tronic structure of the biphenyl skeleton consistent with the heteroatom lying at a node in the singly occupied... 

The wood-derived biomass was delivered dry in batches of about 2 m in chipped and dried to < 10% moisture content. Two orujillo samples were delivered, after they had been dried up to about 10% moisture content. One of them is from the direct olive oil production process (orujillo ) and the other is washed (oruJillo 2) in order to diminish the potassium content as a mean to prevent bed-agglomeration. This potassium-reduction prelreaiment implies a fuel inorganic portion decrease so that a rise in the fuel heating value is caused. 

Fig. 1. Activated magnesium prepared by potassium reduction of MgCl2 in the presence of KI...

Brief mention has been made (538) of the potassium reduction of [Ti(tj-toluene)2] to the green monoanion [Ti(t/-toluene)2] (Section X,A). 

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