Hassel, O. published the artcileStructures of electron-transfer and related molecular complexes in the solid state, SDS of cas: 6443-90-9, the publication is Molecular Physics (1958), 241-6, database is CAplus.
Results obtained in recent years from x-ray investigations of solid addition compounds thought to be formed by electron transfer between mols. containing closed shells are discussed. (1) Addition compounds of ethers (or thioethers) and halogen (X): The arrangement O-X-X (or with S) as well as O-X-X-O (dioxane) is linear. In cases of combinations of 2 different halogens the stronger bond is linked to the donor atom, e.g. RO-I-Cl. This is corroborated by the altered bond distances. (2) Pyridine and ICl (1:1): The whole complex is definitely planar, the bond distances being 2.30 and 2.54 A. for N-I and I-Cl bonds, resp. (3) Hexamethylenetetramine and Br (1:2): Both N-Br-Br are linear, one N-Br and the three C-N bonds forming a nearly regular tetrahedron. Exactly the same configuration is established for Me3N-XY. For X,Y = I the distances for I-I and N-I, resp., 2.85 and 2.27 A. are obtained; if X = I, Y = Cl, the values are 2.53 and 2.30 A. for I-Cl and N-I, resp. These results invalidate Hantsch’s concept of solid addition compounds of the type (R3NX)+Y–. The assumption that the direct reaction products obtained from amines and halogens may without risk be recrystallized from nonaqueous solvents is also fallacious. As regards the structure of charge-transfer complexes, the space group (C 2/m) is determined as the most likely one for C6H6.Br2. The crystal is built of chains consisting of alternating C6H6 and Br2 mols. with the Br atoms symmetrically located about the common major axis of 2 neighboring C6H6 rings. The Br-Br distance differs little from the one in the isolated mol. The distance Br → center of nearest ring amounts to 3.36 A. Crystal structures of addition compounds between ethers and mols. containing active H are also being studied. There exists a bond between O of Et2O and C of CHCl2Br, the O-H-C separation being 3.1 A. It is certain that the 1:1 compound of dioxane and H2SO4 is built of chains, alternating in the components, with both H atoms of the acid taking part in H-bonding with the O atoms of the ether. The O-H-O bond appears to be of normal length. The surprisingly short N-X distances indicate a bond not essentially weaker than ordinary covalent bonds, whereas the lengthening of the adjacent X-X distances in comparison to X2 purports weakening. As both X atoms are linked to the O atoms of dioxane in the crystalline addition compounds, there is strong indication that the second X in 1:1 complexes, evidently present in liquid mixtures, is essentially not altered by bond formation between O and the first X. It is, therefore, suggested that the X, which is directly bound to the donor, forms a 10-electron system, whereas the second X retains its original octet. In this case a linear arrangement would be expected (viz. I3–), as is found. In regard to the probable structure of addition complexes in liquid mixtures it is believed that the amine-X2 and ether-X2 complexes exhibit the linear arrangement. The keto-halogen structures (1:1) in the solid state are predicted to be chains, each keto O being linked to 2 independent X atoms; in this case an angle of about 110° is to be expected between 2 linear O-X-X-O arrangements meeting in the keto O.
Molecular Physics published new progress about 6443-90-9. 6443-90-9 belongs to iodides-buliding-blocks, auxiliary class Pyridines, name is Pyridine Iodochloride complex, and the molecular formula is C5H5ClIN, SDS of cas: 6443-90-9.
Referemce:
https://en.wikipedia.org/wiki/Iodide,
Iodide – an overview | ScienceDirect Topics – ScienceDirect.com