Bivalent Derivatives

Kimura, E. Miki, K. Mizumachi, and T. Ishimori, Chem. Letters, 1976, 1325. 

Anderson, Acta Chem. Scand. (A), 1976, 30, 229. I. Lofving, Acta Chem. Scand. (A), 1976, 30, 715. 

Figiue 31 Structure of Sn(edaa), showing the two equivalent disordered positions of the edaa ligand 

Brunel-Laiigt, I. Tordjman, and A. Durif, Acfa Cryst., 1976, B32, 3246. 

Figore 34 Environments of tin ions in Sn2(0H)P04 (Reproduced by permission from Inorg. Chem., 1976, 15, 1810) 

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Also, the higher alkyl derivatives of lead are not as efficient as the tetraethyl compound. Thus, the butyl triethyl lead derivatives are only about 85 per cent as effective in suppressing knock as is the tetraethyl compound.18 The dibutyl diphenyl lead compounds range from 33 to 45 per cent as good as lead tetraethyl. While the various quadrivalent derivatives of lead show varying degrees of antiknock action, the bivalent derivatives with a few exceptions show no action. 

Receptor binding properties for xanomeline, CDD-0102 and two bivalent derivatives at M, and M2 receptors expressed in A9 L cells Binding data (K values) were from competition assays utilizing [ H](/ )-QNB as the radioligand. Data represent the mean ( S.E.M.) from two to five assays for each compound, n.d., not determined. 

Bivalent radicals derived from saturated unbranched alkanes by removal of two hydrogen atoms are named as follows (1) If both free bonds are on the same carbon atom, the ending -ane of the hydrocarbon is replaced with -ylidene. However, for the first member of the alkanes it is methylene... 

Bivalent radicals derived from unbranched alkenes, alkadienes, and alkynes by removing a hydrogen atom from each of the terminal carbon atoms are named by replacing the endings -ene, -diene, and -yne by -enylene, -dienylene, and -ynylene, respectively. Positions of double and triple bonds are indicated by numbers when necessary. The name vinylene instead of ethenylene is retained for —CH=CH—. 

The name phenylene o-, m-, or p-) is retained for the radical —C5H4—. Bivalent radicals formed from substituted benzene derivatives and having the free valences at ring atoms are named as substituted phenylene radicals, with the carbon atoms having the free valences being numbered 1,2-, 1,3-, or 1,4-, as appropriate. 

Bivalent radicals of the form O—Y—O are named by adding -dioxy to the name of the bivalent radicals except when forming part of a ring system. Examples are —O—CHj—O— (methylene-dioxy), —O—CO—O— (carbonyldioxy), and —O—SOj—O— (sulfonyldioxy). Anions derived from alcohols or phenols are named by changing the final -ol to -olate. 

Bodi tin and lead from Group IV ean form valeney two and four eompounds. Two of die four outer eleetrons ean behave as inert when die atoms are bivalent. Bivalent tin (stannous) derivatives are eovalent whereas die nitrate and sulphate of bivalent lead (plumbous) are ionie. Some tetavalent eompounds sueh as die hydrides and ehloride are unstable, e.g. ... 

In recent years, tnflate derivatives of bivalent iodine have found more and more applications as versatile reagents in organic synthesis [7i5, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145] p.-Oxo-bi [(trifIuoramethanesulfonyloxy) (phenyl)iodine], which is readily available from lodosobenzene and tnflic anhydride (equation 44), is especially valuable for the preparation of alkynyl lodonium Inflates from silyl- or stannylacetylenes [136] (equation 70)... 

Cyclic acetals formed by the reaction of saccharides or saccharide derivatives with aldehydes or ketones are named in accordance with 2-Carb-24.1, bivalent substituent names (formed by general organic nomenclature principles) being used as prefixes. In indicating more than one cyclic acetal grouping of the same kind, the appropriate pairs of locants are separated typographically when the exact placement of the acetal groups is known. 

Molecular compounds of bivalent tin are in all cases bent molecules, the angle between the substituents approaching 90°. Only the it-pseudo-bound cyclopentadienyl derivatives deviate considerably from this angle (120 and 144°, respectively) ... 

If one assumes to a first approximation that the contraction of the cell is a linear function of the covalence of the metal-ligand bond, one can derive for the bivalent ions the following equations ... 

An organic compound that contains the bivalent -O-O- structure and which may be considered to be a structural derivative of hydrogen peroxide where one or both of the hydrogen atoms has been replaced by an organic radical. 

Combining [Ca2+] and [Mg2+] in this expression, derived from ion exchange equilibrium considerations, is not strictly valid but cause litte deviation from more exact formulations and is justified because these two bivalent cations behave similarity during cation exchange. 

In a similar way fulminic acid, another derivative of bivalent carbon, which has been accurately investigated and for which the carboxime >C NOH constitution has been established, is decomposed into formic acid and hydroxylamine (see experiment on p. 159). 

Mention should also he made of radicles with bivalent nitrogen which are derived from hydrazines, the so-called hydrazyls. They are deeply coloured compounds which are obtained by dehydrogenation of tertiary hydrazines and form equilibrium mixtures with colourless tetrazanes, which dissociate into these free radicles (S. Goldschmidt),... 

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