# Structures, Rotational Barriers, and Thermochemical Properties of Chlorinated Aldehydes
and the Corresponding Acetyl (CC^{•}O) and Formyl Methyl Radicals (C^{•}CO) and
Additivity Groups

journal contribution

posted on 15.12.2001, 00:00 by Li Zhu, Joseph W. BozzelliChlorinated formyl methyl radicals (C

^{•}CO) are the stable keto forms of chlorovinoxy radicals formed by cleavage or abstraction of the weak O−H bonds of chlorovinyl alcohols. Thermochemical properties, Δ*H*_{f}°_{298},*S*°_{298}, and*C**°(*_{p}*T*) (5 K ≤*T*≤ 6000 K), are computed by density functional B3LYP/6-31G(d,p) and B3LYP/6-311+G(3df,2p), ab initio QCISD(T)/6-31G(d,p), and composite CBS-Q calculation methods for chlorinated aldehydes and the corresponding chlorinated acetyl and formyl methyl radicals: CH_{3}CHO (**1**), CH_{3}CClO (**2**), CH_{2}ClCHO (**3**), CH_{2}ClCClO (**4**), CHCl_{2}CHO (**5**), CHCl_{2}CClO (**6**), CCl_{3}CHO (**7**), CCl_{3}CClO (**8**), CH_{3}C^{•}O (**9**), CH_{2}ClC^{•}O (**10**), CHCl_{2}C^{•}O (**11**), CCl_{3}C^{•}O (**12**), C^{•}H_{2}CHO (**13**), C^{•}H_{2}CClO (**14**),*E*-C^{•}HClCHO (**15**),*Z*-C^{•}HClCHO (**16**), C^{•}Cl_{2}CHO (**17**),*E*-C^{•}HClCClO (**18**),*Z*-C^{•}HClCClO (**19**), C^{•}Cl_{2}CClO (**20**). Molecular structures and vibration frequencies are determined at the B3LYP/6-31G(d,p) level of theory. Vibration frequencies are scaled for zero-point energies and thermal corrections. Two to four isodesmic reactions are utilized at each calculation level to determine Δ*H*_{f}°_{298}of each species. Contributions to*S*°_{298}and*C**°(*_{p}*T*) from translation, vibration, and external rotations are calculated using the rigid-rotor-harmonic-oscillator approximation based on the B3LYP/6-31G(d,p) structures. Hindered internal rotational contributions to entropies and heat capacities are calculated by summation over the energy levels obtained from direct diagonalizations of the Hamiltonian matrix of the internal rotation. The bond energies of C−H and C−Cl in chloroaldehydes are also calculated.## History

## Usage metrics

## Read the peer-reviewed publication

## Categories

## Keywords

Additivity Groups Chlorinated formyl methyl radicalsChlorinated Aldehydesvibration frequenciesCClQCISDCHOB 3LYP structuresB 3LYP levelchlorovinoxy radicalsRotational BarriersCHClThermochemical PropertiesFormyl Methyl Radicalscalculation levelisodesmic reactionsThermochemical propertiesheat capacitiesCHCCMolecular structureschlorinated aldehydesCClOchlorovinyl alcoholsketo formsB 3LYPchlorinated acetylHamiltonian matrixenergy levelsbond energiesVibration frequencies