Complex dynamics variables for molecules and molecular clusters

Komarov, V. V.; Schmidt, L. Ph. H.; Fritsch, Hans-Walter; Jungclas, H.

doi:10.1016/0927-0256(94)90068-x

Cited by 15 publications

(18 citation statements)

References 2 publications

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“…The influence of the dipoledipole interaction in the antenna structure generates M r collective vibrational states [21] in the energy interval […”

Section: Collective Vibration Excitation In Hydrocarbon Antennas (Excmentioning

confidence: 99%

“…The transition of the excimol energy to the trap bond eventually causes dissociation of this bond, which occurs during a time period less than the excimol lifetime (τ ex ∼ 10 −11 s). Taking into account the Frank-Condon effect, an estimation shows that dissociation of a trap bond occurs with highest probability, if the sum of energies gathered by the trap bond just exceeds its binding energy [20][21][22].…”

Section: Introductionmentioning

confidence: 99%

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Hydrocarbon Substructures of Organic Molecules as Antennas and Amplifiers for External mid-IR Radiation

Jungclas¹,

Komarov²,

Popova³

et al. 2007

Zeitschrift Für Physikalische Chemie

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We consider organic polyatomic molecules, which contain hydrocarbon antennas i.e. substructures of identical periodically located C-H dipoles. In these antennas collective vibrational excitations (excimols) are coherently produced by resonant absorption of photons in the mid-IR energy range. The energy of an excimol is lower than the energy of the first vibrational excited state of an isolated antenna dipole and the excimol lifetime does not exceed 10 −11 s. The excimols are excited successively and independently in the C-H dipoles resulting in energy accumulation in the antenna. The accumulated vibrational energy can be transmitted to a trap bond, which is also forming a dipole inside the molecule, however, not acting as an antenna. The trap bond is cleaved, if the absorbed excimol energy is equal to its dissociation energy. Under certain conditions the accumulated energy can be transformed to electronic excitation of a molecular constituent resulting in molecular luminescence. The emitted luminescence photons have energies much higher than the energy of each of the IR photons, which induce an excimol. Thus the hydrocarbon antennas in organic molecules are able to work as amplifiers of external IR radiation. These intramolecular energy transmission processes complete within a time period less or equal to the excimol lifetime and thus can be referred to as super-fast compared to typical time scales calculated by statistical models. The model presented here predicts that the probabilities of the considered processes resonantly depend on the frequency and intensity of IR radiation. The presented theoretical model is supported by the results of our experimental studies of the considered type of molecular fragmentation.

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“…The influence of the dipoledipole interaction in the antenna structure generates M r collective vibrational states [21] in the energy interval […”

Section: Collective Vibration Excitation In Hydrocarbon Antennas (Excmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Hydrocarbon Substructures of Organic Molecules as Antennas and Amplifiers for External mid-IR Radiation

Jungclas¹,

Komarov²,

Popova³

et al. 2007

Zeitschrift Für Physikalische Chemie

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“…Since the diatomic groups in the molecular chain are considered as electric dipole oscillators, the dipole moments d i and d j of the groups (i) and (j) can be presented by the equation (4) In (4) the term eD 0 is the amount of the dipole moment of any diatomic group in the chain, r is the variable, r 0 the average length of the dipole groups, and n k is the unit vector in the direction of the dipole moment. The interaction energy E ij can be calculated [14,15] using the first approximation of the perturbation theory by the expression (5) The term M 01 is given by the matrix element ·j 0 (r) |r | j 1 (r)Ò , where j 0 (r) and j 1 (r) are the oscillator wave functions of the ground and first excited states, respectively, for any two neighboured groups (i and j). Q ij is defined by the expression Q ij = cosq i x cos q j x + cosq i y cos q j y + cosq i z cos q j z ,…”

Section: Excimol Excitationmentioning

confidence: 99%

“…This energy difference is caused by the energy E tr required for energy transitions within the chain from one diatomic oscillator to another. These tansitions are due to resonance dipole-dipole interactions between identical molecular dipoles and the transition energy E tr which strongly depends on the dipole moment of the diatomic groups and on the three-dimensional structure of the chain [14,15]. The excimol lifetime t ex is larger than the lifetime t 01 of the excitation of an isolated diatomic oscillator in the first vibrational state, because the resonance interaction of the diatomic dipoles within the chain decreases the probability of vibrational relaxation in each dipole.…”

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confidence: 99%

Resonant IR Photon Induced Dissociation in Organic Molecules with Chain-like Substructures

Jungclas

Schmidt

Komarov

et al. 2002

Zeitschrift Für Naturforschung A

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IntroductionPhoton induced dissociation (PID) of molecules due to action of low intensity IR radiation is the subject of several experimental investigations [1][2][3][4][5][6][7][8][9][10][11][12]. The interest in this field arose, as information of molecular dissociation by IR photons is important not only for the development of quantum chemistry of organic molecules and for the theory of laser beam interactions with large molecules, but also for practical applications. It was shown experimentally that the PID of molecules consisting of chain-like substructures can be induced resonantly by IR radiation with frequencies which do not coincide with the vibrational frequencies of the diatomic valence groups contained in these molecules [4,5]. Also, it was shown that IR photon induced dissociation (IR-PID) leads with high probability to fragments consisting of small atomic groups. These groups are mainly the end groups of the chain-like substructures inside the irradiated molecules [6][7][8][9][10][11][12]. The abundance of different fragments depends on the photon fluence, on the number of diatomic groups in the chains and on the corresponding dissociation energies [6][7][8][9][10][11][12].In the present work a model for the dissociation of organic molecules with chain-like substructures by IR-PID is suggested. The model is based on the excimol theory for excitation and fragmentation of organic molecules, which was worked out previously [13]. In the frame of the excimol theory the collection of internal molecular energy occurs in chain-like molecular substructures consisting of identical diatomic groups with significant dipole momenta. In these chains many collective vibrational states (excimols) with frequency w ex are induced by a resonant external periodic field, e.g. IR photons. The excimol energy E ex = h w ex is less than the energy E 01 = h w 01 of the first vibrational state of an isolated diatomic quantum oscillator. This energy difference is caused by the energy E tr required for energy transitions within the chain from one diatomic oscillator to another. These tansitions are due to resonance dipole-dipole interactions between identical molecular dipoles and the transition energy E tr which strongly depends on the dipole moment of the diatomic groups and on the three-dimensional structure of the chain [14,15]. The excimol lifetime t ex is larger than the lifetime t 01 of the excitation of an isolated diatomic oscillator in the first vibrational state, because the resonance interaction of the diatomic dipoles within the chain decreases the probability of vibrational relaxation in each dipole. For example, the excimol lifetime t ex in a (CH 2 ) n chain is two orders of magnitude higher than the lifetime t 01 of the excitation of an isolated CH-group.Resonant excimol excitation can be induced by periodic electromagnetic fields including IR-fields, if the frequency of the field is equal to the excimol frequency. Several excimols can be excited independently in a chain. They are not accumulated in a single diat...

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“…A band of collective low-energy vibrational states can arise in (CH 2 ) n , due to the relatively high dipole moment of the CH-bonds and the small distance between them of about 1.5Å in the chain. The state in the band with the lowest energy E ex = 0.07 eV and the lifetime τ ex = 5 · 10 −11 s is called excimol [24]. An excimol can travel from one CH-dipole to the neighbour dipole along the antenna due to the resonant dipole-dipole interaction between the CH-valence bonds in the time interval τ tr = 10 −14 s without energy loss and phase change.…”

Section: Alkanes As Antennas For Mid-ir Radiation and Molecular Energmentioning

confidence: 99%

Vibration Energy Accumulation and Redistribution in Organic Molecules Irradiated by Infrared Photons

Jungclas

Popova

Komarov

et al. 2007

Zeitschrift Für Naturforschung A

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A theoretical approach to the dissociation and low-energy electronic excitation of polyatomic organic molecules with donor and acceptor substructures is suggested. The donor hydrocarbon molecular substructures can serve as antennas for low-energy infrared (IR)-photon absorption, which coherently induce collective vibrational excitations (excimols). Due to dipole-dipole interactions, the accumulated energy can transit to the molecular acceptors: dipole-type trap-bonds or molecular parts with π-electron orbits. The analytical expressions for the probability functions of molecular fragmentation and electronic excitation induced by IR-multiphoton absorption are derived. The vibrational energy accumulation and redistribution in the molecules of diphenylalkanes irradiated by infrared photons are considered from the presented point of view.

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Complex dynamics variables for molecules and molecular clusters

Cited by 15 publications

References 2 publications

Hydrocarbon Substructures of Organic Molecules as Antennas and Amplifiers for External mid-IR Radiation

Hydrocarbon Substructures of Organic Molecules as Antennas and Amplifiers for External mid-IR Radiation

Resonant IR Photon Induced Dissociation in Organic Molecules with Chain-like Substructures

Vibration Energy Accumulation and Redistribution in Organic Molecules Irradiated by Infrared Photons

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