A cryosolution FTIR and ab initio study of the blue shifting C–H···F hydrogen bonded complexes F2ClCH·FCD3 and Cl2FCH·FCD3

Rutkowski, K.S.; Herrebout, Wouter A.; Меликова, С.М.; Veken, B.J. van der; Koll, A.

doi:10.1016/j.chemphys.2008.09.009

Cited by 18 publications

(9 citation statements)

References 38 publications

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“….Y halogen bonds, interactions involving the fluorine and chlorine atoms in methyl fluoride (CH 3 F), ethyl fluoride (C 2 H 5 F), methyl chloride (CH 3 Cl), and ethyl chloride (C 2 H 5 Cl) were also studied. The choice for these alkyl halides was based on earlier observations [97,110,113,[130][131][132]143] showing that these compounds can act as Lewis bases, and in earlier studies were observed to form complexes with C-H donors such a CHF 3 , CHCl 3 , CHBrClCF 3 , and other Lewis acids such as HCl, HBr, BF 3 , and BCl 3 . The Lewis bases studied were limited to alkyl fluorides and alkyl chlorides, as measurable concentrations of the weak halogen-bonded complexes could only be observed at temperatures below 145 K, i.e., in LAr and LKr, while alkyl bromides and iodides show a limited solubility in these conditions.…”

Section: C-x F and C-x Cl-bonded Complexes: Alkyl Fluorides Amentioning

confidence: 98%

Infrared and Raman Measurements of Halogen Bonding in Cryogenic Solutions

Herrebout

2014

Topics in Current Chemistry

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Because they create a weakly interacting environment which, combined with the low temperatures used, leads to small bandwidths and thus facilitates the detection of complex bands only slightly shifted from the monomer modes, solutions in liquefied inert gases have proven to be an ideal medium to study molecular complexes held together by weak and medium-strong C-X…Y (with X=I, Br, Cl and Y=O, N, S, F, Cl, π,…) halogen bonds. In this chapter, experimental setups for infrared and Raman study of cryosolutions are described, and general methodologies used to examine weakly bound molecular complexes are discussed. The methods are illustrated using data obtained for a variety of halogen-bonded complexes involving, amongst others, the trifluorohalomethanes CF3Cl, CF3Br, and CF3I, and a variety of Lewis bases. The results are compared with theoretical data obtained from ab initio calculations, and with experimental and theoretical data obtained for complexes involving weak C-H proton donors such as CHF3. Preliminary data for mixed proton donor/halogen donors such as CHClF2, CHBrF2 are also discussed.

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Section: C-x F and C-x Cl-bonded Complexes: Alkyl Fluorides Amentioning

confidence: 98%

Infrared and Raman Measurements of Halogen Bonding in Cryogenic Solutions

Herrebout

2014

Topics in Current Chemistry

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“…29 Due to the low abundance of the complexes and the weaker intensity of overtone and combination vibrations in the near-IR (NIR) region, the number of NIR spectroscopic studies of hydrogen bonded complexes is limited. The available NIR studies of hydrogen bonded complexes are mostly carried out either at very low temperatures, 36,[42][43][44][45][46] or in organic solutions, [47][48][49][50][51] conditions that are less relevant to the atmosphere. Recently, gas phase NIR spectra of the hydrogen bonded complex MeOH-TMA were recorded to about 6500 cm À1 .…”

Section: Introductionmentioning

confidence: 99%

Fundamental and overtone vibrational spectroscopy, enthalpy of hydrogen bond formation and equilibrium constant determination of the methanol–dimethylamine complex

Mackeprang

Kjaergaard

2013

Phys. Chem. Chem. Phys.

112

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We have measured gas phase vibrational spectra of the bimolecular complex formed between methanol (MeOH) and dimethylamine (DMA) up to about 9800 cm(-1). In addition to the strong fundamental OH-stretching transition we have also detected the weak second overtone NH-stretching transition. The spectra of the complex are obtained by spectral subtraction of the monomer spectra from spectra recorded for the mixture. For comparison, we also measured the fundamental OH-stretching transition in the bimolecular complex between MeOH and trimethylamine (TMA). The enthalpies of hydrogen bond formation (ΔH) for the MeOH-DMA and MeOH-TMA complexes have been determined by measurements of the fundamental OH-stretching transition in the temperature range from 298 to 358 K. The enthalpy of formation is found to be -35.8 ± 3.9 and -38.2 ± 3.3 kJ mol(-1) for MeOH-DMA and MeOH-TMA, respectively, in the 298 to 358 K region. The equilibrium constant (Kp) for the formation of the MeOH-DMA complex has been determined from the measured and calculated transition intensities of the OH-stretching fundamental transition and the NH-stretching second overtone transition. The transition intensities were calculated using an anharmonic oscillator local mode model with dipole moment and potential energy curves calculated using explicitly correlated coupled cluster methods. The equilibrium constant for formation of the MeOH-DMA complex was determined to be 0.2 ± 0.1 atm(-1), corresponding to a ΔG value of about 4.0 kJ mol(-1).

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“…The greatest difference of the A 1g n(CH) between the most blue shifted salt ( 1) and the most red shifted one ( 4) is ca. 40 cm À1 , which should correspond to a difference of 0.001 A ˚in the C-H bond distance, 26 which is not experimentally accessible.…”

Section: Discussionmentioning

confidence: 98%

Blue and red shift hydrogen bonds in crystalline cobaltocinium complexes

et al. 2012

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Typical hydrogen-bonded cobaltocinium salts of formula [Cp 2 Co + ][A À ] [with Cp = C 5 H 5 and A = PF 6 ( 1), AsF 6 ( 2), SbF 6 ( 3), I ( 4), I 3 ( 5), Co(CN) 6 ( 6), Co(CO) 4 ( 7), Br 3 ( 8), FeI 4 ( 9) and HCl 2 ( 10)] were studied by means of a combined structural, spectroscopic (IR, Raman, solid-state NMR) and theoretical approach. The solid-state vibrational spectra show blue or red shift hydrogen bond behavior depending on the anionic species, i.e. high-or low-frequency n(CH) shift with respect to the solution value. The crystal structure of the new complex [Cp 2 Co + ][SbF 6 À ], a blue-shifted system, is reported while the [Cp 2 Co + ][I À ] complex, a red-shifted system disordered at room temperature, reveals a novel ordered polymorph at 150 K. The weak interactions (CÁ Á ÁH, HÁ Á ÁH, HÁ Á ÁX, CÁ Á ÁX) between cations and anions were analyzed by means of the Hirshfeld surfaces model, which permits their clear graphic visualization. HS fingerprint plots and normalized contact distances visually describe the difference between blue-and red-shifted complexes. Chemical shift tensors and shielding anisotropy values of the Cp carbon atoms, extracted from 13 C CPMAS solid-state NMR spectra, allow the evaluation of Cp rotational motions which are related to the intermolecular contact extent. Finally, a DFT computational model is able to rationalize all the experimental data. It shows that the prevalence of one between two forces, that is, the attractive polarization of C-H bonds and the repulsive effect of electronic clouds, leads to the blue or red shift phenomenon.

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A cryosolution FTIR and ab initio study of the blue shifting C–H···F hydrogen bonded complexes F2ClCH·FCD3 and Cl2FCH·FCD3

Cited by 18 publications

References 38 publications

Infrared and Raman Measurements of Halogen Bonding in Cryogenic Solutions

Infrared and Raman Measurements of Halogen Bonding in Cryogenic Solutions

Fundamental and overtone vibrational spectroscopy, enthalpy of hydrogen bond formation and equilibrium constant determination of the methanol–dimethylamine complex

Blue and red shift hydrogen bonds in crystalline cobaltocinium complexes

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