C—I—O bond angle

Single-crystal X-ray structural data are all consistent with the pseudo-trigonal bipyramidal, or T-shaped geometry, of alkynyliodonium species. In all known cases, the aryl group occupies an equatorial position, whereas the alkynyl moiety and the counter ion occupy apical positions. The alkynyl-iodine bond length is about 2.0 A and the I -O distances to the nearest sulfonate anion vary from 2.56 to 2.70 A. The C—I—O bond angles vary from 166° to 172° and the C—I—C bond angles are between 90° and 95°. 

Products 113—115 are isolated as thermally stable, white, microcrystalline solids. Structures of two (114 and 115) were unambiguously established by single-crystal X-ray analysis (1996MC50, 1996H47). In particular. X-ray structural data for 114 revealed the expected hypervalent iodine distorted T-shaped geometry with an endocyclic C—I—O bond angle of 78.2° and... 

Acetoxybenziodazole 150 (as a solvate with acetic acid) has the expected distorted T-shaped geometry at the iodine atom with an N—I—O bond angle of 162.1°. Bond lengths to the iodine center [I—N (2.101 A), I—O (2.34 A), and I—C (2.106 A)] are aU within the range of typical single covalent bonds in organic derivatives of polyvalent iodine and are in good... 

The C0O2 layer is formed by the edge-shared CoC>6 octahedra which are compressed along c-axis (Fig. 1). The rhombohedral distortion of the CoC>6 octahedra is measured by the deviation of the O-Co-O bond angle from 90°, 95° 99° [2, 24-27], The distortion leads to the crystal-field splitting in t2g states of 3[Pg.202]

The difference in the reaction profiles that involve transition states A and B for the oxygen transfer are quite subtle, i.e. merely the O —C —O bond angle in the attacking oxygen atom donor. In the intact dioxirane this bond angle is ca. 60°, while in the dioxyl diradical it is at most ca. 110°. 

Table 11.2.A I c-O bond distances [A] and O Tc-O bond angles of perlechnelatcs at room temperature 118,20,22,44],...

The potential-energy surface for the rearrangement of cis- and tra i-4,5-epoxyhexan-l-ol with acid or the Lewis acid BF3 to five- and six-membered cyclic ethers has been examined by ab initio methods. The preference for furan rather than pyran formation is attributed to the more favourable O—C—O bond angles in the transition structures for furan formation. 

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