Molecular complexes of substituted thiophens with σ and π acceptors. Charge transfer spectra and ionization potentials of the donors

Abstract

Charge transfer complexes of substituted thiophens as donors with tetracyanoethylene, 2,3dichloro-5,6-dicyano-p-benzoquinone, chloranil and iodine have been studied spectrophotometricall y. From the energies of the charge transfer transitions, the ionization potentials of the donors have been obtained. Comparison with those measured by electron-impact mass spectrometry, shows that the thiophens behave as T donors with all four acceptors. In the case of iodine the stability constants of the complexes support a T+U* interaction. Some evidence is given for the role of inner valence orbitals in the complexes.

Solvent effects on the spectrokinetic studies on the molecular complexes of dextromethorphan and atenolol drugs with DDQ

“…Of the many applications of CT complexes, one important application is to calculate the ionization potential of the donor. The ionization potential (I p ) of the highest filled molecular orbital of the donor was estimated from CT energies of its complexes with the acceptor making use of the empirical equations reported in the literature [26]. The calculated I p values for molecular orbital participating in the CT interaction of the drugs are listed in Table I.…”

Molecular Complexes of some N-Aryldithiocarbamates with π-Electron Acceptors

“…The ionization potential of the HOMO (n) on the donors 1±4 was estimated from the CT energies of their complexes with TCNE, CHL, and DDQ by adopting the empirical equations reported by Aloisi and Pignataro [14]. The values obtained are listed in Table 1.…”

Spectroscopic and thermal studies on charge-transfer complexes of perhydroisoquinoline with p-chloranil, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, and 7,7′,8,8′-tetracyanoquinodimethane

“…The dissociation energy (W) can be calculated from the corresponding CT energy (E CT ), donor ionization potential (I p ), and electron affinity of the acceptor (CHL, 1.37 and DDQ, 1.95 eV) [21][22][23][24][25][26]. The estimated value of W in the case of DDQ as the acceptor is 4.36 eV.…”

“…3, for the reaction mixtures of PHIQ with CHL, DDQ, and TCNQ in CHCl 3 , respectively. Oscillator strengths (f) [20][21][22][23][24][25][26] and transition dipole moments (μ) of the CT complexes [21][22][23][24][25][26] ( Table 2) have been calculated from the following equations:…”