Hydroxyl bonds

Paulissen, R. Reimlinger, H. Hayez, E. Hubert, A. J. Teyssie, P. Transition metal catalysed reactions of diazocompounds. II. Insertion in the hydroxylic bond. Tetrahedron Lett. 1973, 14, 2233-2236. 

Lignin contains interconnected aromatic and aliphatic rings [11] (see figure 5) and aliphatic chains containing about 30 percent oxygen by weight in the form of ether, carbonyl, and hydroxyl bonds. 

Phenol is a rare example of a stable enol (pronounced ene-ol ), with a hydroxyl bonded to a C=C bond. Most enols tautomerize to form a ketone. 

A feature of the structures of complexes of hydroxyalkanoates is that the metal-ionized-hydroxyl bond length is usually shorter than the corresponding metal-protonated-hydroxyl bond length. 

The values given for hydroxyl bond angles are only approximate since an accurate value would require allowance for bond angles and inter-atomic distances which have not been determined for these compounds. 

Fia. 1.—a. Diagram of Reeves Cl Conformation of the Pyranoside Ring Proposed for Methyl 4,6-Benzylidene-a-D-altropyranoside, with the Hydroxyl Groups Shown on Carbon Atoms 2 and 3. b. Detailed View of Carbon Atoms 2 and 3 with the Hydroxyl Bonds Which Have a Projected Angle of about 180° in the Cl Conformation for This Compound. 

The local full NRG appears then as a direct product of two commutable subgroups the restricted NRG corresponding to the internal motions, Uf, and the external rotation symmetry subgroup corresponding to the external rotation. The restricted NRG is seen to be smaller than the exact full NRG, and the external one isomorphic to the symmetry point group of the molecule in its most symmetric configuration, Csu, in which the hydroxylic bonds are colinear with the C-0 bonds. 

For the compounds with amphoteric properties, the existence of coordination groups Me(OH)4 (tetrahedrons) and Me(OH)g (octahedrons) is characteristic hydroxyl bonds exist between separate groups. Molecular structures are characteristic of the compounds with clearly expressed acidic properties. This means that lattice sites are occupied by molecules bound to each other by hydrogen bonds. Since this leads to the decrease of lattice strength, some acids are liquids under normal conditions, while all the bases and amphoteric hydroxides are solids. 

Houllevigue s formula for latent heat of evaporation in capillary tube, 369 Huggins s molar volume formula, 21 hydrogen bonds, 3, 41 hydrometer, 14 Nicholson s, 14 hydrostatic balance, 14 pressure and vapour pressure, 367 hydroxyl bonds, 41 hylotropic phases, 229 hyperbola, 421, 423 hyperbolic paraboloid, 431 hyperboloid, 429, 430 hysteresis of contact angle, 166... 

Subclassifications of H Bonds. Subclassifications among H bonds have been proposed since the earliest studies of the H bond. For a time there were proponents of a distinction between a hydrogen and a hydroxyl bond (200). This distinction was no doubt stimulated by the incorrect belief that the IR absorption of the O—H stretching mode disappears in some cases (707) and not in others. When it wtis found that the apparent disappearance was in fact due to broadening of the band, the hydroxyl bond lost favor (103). (See also 2067, 920, 919.)... 

H bond hydrogen bond hydrogen bridge hydroxyl bond Dimroth ring chelate ring proton bond... 

Biomass tars are known to be very complex mixtures which contain significant amounts of polar compounds that can potentially form hydroxyl bonds. This means that current vapor pressure estimation techniques are not only difficult to apply, but are inaccurate for mixtures with significant oxygen functionalities. Therefore we have chosen to approach this problem from an experimental standpoint. 

Silicon-hydroxyl Bond in Trialkylsilanols. J. Amer. chem. Soc. 68, 2282 (1946). 

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