Carbon-oxygen distance

Likewise the experimentally measured pattern of carbon-oxygen bond lengths m acetic acid is different from that of acetate ion Acetic acid has a short C=0 and a long C—O distance In ammonium acetate though both carbon-oxygen distances are equal... 

Suppose we put the carbons at (a) and the oxygens at (6). In this case an oxygen atom would be equidistant from G1 and C2 (Fig. 176 a) in other words its distance from the carbon atom in its own molecule would be the same as its distance from a carbon atom in a different molecule, which is very unlikely. Suppose now we put carbons at a) and oxygens at (c) the same situation develops—an oxygen would be equidistant from Cx and C 3 (Fig. 176 b). ()nly by putting both carbons and oxygens at two sets of (c) positions, with different values of z (Fig. 176 c), can we keep the intramolecular and intermolecular carbon-oxygen distances different from each other. 

The carbon-oxygen distance in this molecule is known6 to be 1.159 A. If one structure 0=C=0 alone represented the molecule the distance should be 1.18 A, the double-bond length with the adjacent-bent-bond... 

Two substances having the same molecular formula, C/tHgO, were examined in the gaseous state by electron diffraction. The carbon-oxygen distance was found to be 143 pm in compound A and 124 pm in compound B. What can you conclude about the structures of these two compounds ... 

In compound A the carbon-oxygen distance is the sum of the single-bond covalent radii of carbon and oxygen, indicating a single bond (77 pm + 66 pm =143 pm). 

In compound B, the carbon-oxygen distance is close to that predicted for a double bond, 122 pm. Then, the oxygen must be terminal. A structure that conforms to these data is 2-butanone [Fig. 9-37(b)]. 

Table 5.14. Calculated C NMR shielding components average diamagnetic (o-J ) and paramagnetic (cjpJ components, overall average (a ), and shielding anisotropy (ct - Oj ) as a function of carbon-oxygen distance, R(C-O), for CO/-...

Table 5.16. Calculated electric-dipole polarizability for COj " and refractive index n of calcite in sodium D light, for carbon-oxygen distance = 1.29 A...

The molecule is linear with carbon-oxygen distances of 1.15 A, which is considerably shorter than that calculated for a double bond (1.22 A). Two TT-bond systems are expected, in perpendicular planes, but each would extend over all centres cf. carbon suboxide) contributing slightly more than half a n bond in each link. 

V(CO)6 and [V(CO)6] are both octahedral. Which has the shorter carbon-oxygen distance The shorter vanadium-carbon distance ... 

In the drawing of the molecular structure, one oxygen atom is indicated to be bonded to the adjacent carbon atom by a double bond, and the other by a single bond. In fact, studies of the molecular structure have shown that the two carbon-oxygen distances are equal, with the value 1.25 A. This fact is accounted for by saying that the double bond resonates between the two oxygen atoms. 

The strength of binding of the carbonyl ligands apparently increases slightly, but we believe significantly, as the number of carbonyl ligands per metal atom decreases, an effect evident from metal-carbon and carbon-oxygen distances. The total enthalpy of the metal-metal bonds per metal atom, M)/x,... 

In addition, to determine the carbon-oxygen distance of such hydrogen bond systems, the dipolar recoupling experiment have been performed by... 

In carboxylic acids, extensive thermal motion or disorder over the —COOH group quite often causes the carbon-oxygen distances to vary over ranges of 1.30-1.25 and 1.25-1.20 A for the C=0 and C—O bonds, respectively. Test calculations on benzoic acid using either the observed distances of 1.275 and 1.264 A or renormalized distances of 1.30 and 1.22 A show oscillations of 1-2 kJ moU in the packing energy. 

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