Jahn-Teller distortion determinations

The size of the Jahn-Teller distortion is estimated from the value of Req determined from b2 and X for the ground state,... 

The absorption spectrum of the bare Cu Y zeolite was also measured and interpreted using a model of a CuII-0(Sl ) site. The 0-CuII-0 angle was determined to be 117° from optical spectra, in excellent agreement with 115.9° found by X-ray crystallography (20). Based upon the observed spectral splitting of 1800 cm- of the states of Cu -, first order vibronic theory predicted a Jahn-Teller distortion of 0.05-0.06 A along the Cu11- bonds. 

The structure of diphosphallenic radical cations, generated from the allene ArP=C=PAr by electrochemical oxidation, has been examined using EPR spectroscopy. Ab initio calculations including correlation effects at the MP2 and MCSCF levels have determined that two rotamers exist compatible with Jahn-Teller distortion of the allene.146 Anodically generated radical cations of alkyl phosphites [(RO P] and silylphosphites [(RO)2POSiMe3] reacted with alkenes by initial attack at the C=C bond followed by electron transfer, deprotonation, and elimination of an alkyl or trimethylsilyl cation to form identical alkyl phosphate adducts.147 The electron ionization-induced McLafferty rearrangement of n-hexylphosphine afford the a-distonic radical cation CTEPH, the distinct reactivity of which suggests there is no... 

Here /, is the 13C nuclear spin, S is the unpaired electronic spin, and A j- is the Fermi contact hyperfine coupling tensor. This coupling is identical for all 13C nuclei as long as the C60 ion is spherical, but becomes different for different nuclei after the Jahn-Teller distortion leading to an inhomogeneous frequency distribution. The homogeneous width of the 13C NMR lines is, on the other hand, mainly determined by the electron-nuclear dipolar interaction... 

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