To the limit of gas-phase electron diffraction: Molecular structure of magnesium octa(m-trifluoromethylphenyl)porphyrazine

Zhabanov, Yuriy A.; Захаров, А. В.; Giricheva, N. I.; Shlykov, Sergey A.; Койфман, О. И.; Girichev, G. V.

doi:10.1016/j.molstruc.2015.03.010

Cited by 19 publications

(7 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…GED has been continuously under development, allowing the structural determination of increasingly larger molecules; some of this progress is based on the method of including predicate observations . Using advanced evaporation techniques, GED is nowadays able to determine structures as large as C 60 and C 70 , octasilsesquioxane Si 8 O 12 ( p -ClCH 2 C 6 H 4 ) 8 (C 56 H 48 O 12 Si 8 ), or complexes like fac -[Ir(ppy) 3 ](C 33 H 24 N 3 Ir) and magnesium(II) octa(trifluormethylphenyl)porphyrazine (MgC 72 H 32 N 8 F 24 ); the latter is the largest molecule ever studied by GED.…”

Section: Introductionmentioning

confidence: 99%

Intramolecular London Dispersion Interaction Effects on Gas-Phase and Solid-State Structures of Diamondoid Dimers

et al. 2017

View full text Add to dashboard Cite

The covalent diamantyl (CH) and oxadiamantyl (CHO) dimers are stabilized by London dispersion attractions between the dimer moieties. Their solid-state and gas-phase structures were studied using a multitechnique approach, including single-crystal X-ray diffraction (XRD), gas-phase electron diffraction (GED), a combined GED/microwave (MW) spectroscopy study, and quantum chemical calculations. The inclusion of medium-range electron correlation as well as the London dispersion energy in density functional theory is essential to reproduce the experimental geometries. The conformational dynamics computed for CHO agree well with solution NMR data and help in the assignment of the gas-phase MW data to individual diastereomers. Both in the solid state and the gas phase the central C-C bond is of similar length for the diamantyl [XRD, 1.642(2) Å; GED, 1.630(5) Å] and the oxadiamantyl dimers [XRD, 1.643(1) Å; GED, 1.632(9) Å; GED+MW, 1.632(5) Å], despite the presence of two oxygen atoms. Out of a larger series of quantum chemical computations, the best match with the experimental reference data is achieved with the PBEh-3c, PBE0-D3, PBE0, B3PW91-D3, and M06-2X approaches. This is the first gas-phase confirmation that the markedly elongated C-C bond is an intrinsic feature of the molecule and that crystal packing effects have only a minor influence.

show abstract

Section: Introductionmentioning

confidence: 99%

Intramolecular London Dispersion Interaction Effects on Gas-Phase and Solid-State Structures of Diamondoid Dimers

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The shapes of molecular orbitals (MOs) that participate in electronic transitions with large oscillator strengths are shown in Figure 7 and the energy diagram of molecular orbitals for H 2 TTDPz and NiTTDPz is shown in the Figure 8 . The symmetry of the frontier MOs in the NiTTDPz complex is also typical for metal complexes of porphyrazines and tetrakis(1,2,5-thiadiazolo)porphyzarines—a 1u for HOMO and a pair of degenerate orbitals e g * for LUMO [ 26 , 27 , 32 , 40 , 41 ]. The shapes of HOMO orbitals for H 2 TTDPz and NiTTDPz are similar, despite different types of symmetry.…”

Section: Resultsmentioning

confidence: 96%

Molecular Structure, Thermodynamic and Spectral Characteristics of Metal-Free and Nickel Complex of Tetrakis(1,2,5-thiadiazolo)porphyrazine

et al. 2021

Self Cite

View full text Add to dashboard Cite

The Knudsen effusion method with mass spectrometric control of the vapor composition was used to study the possibility of a congruent transition to the gas phase and to estimate the enthalpy of sublimation of metal-free tetrakis(1,2,5-thiadiazolo)porphyrazine and its nickel complex (H2TTDPz and NiTTDPz, respectively). The geometrical and electronic structure of H2TTDPz and NiTTDPz in ground and low-lying excited electronic states were determined by DFT calculations. The electronic structure of NiTTDPz was studied by the complete active space (CASSCF) method, following accounting dynamic correlation by multiconfigurational quasi-degenerate second-order perturbation theory (MCQDPT2). A geometrical structure of D2h and D4h symmetry was obtained for H2TTDPz and NiTTDPz, respectively. According to data obtained by the MCQDPT2 method, the nickel complex possesses the ground state 1A1g, and the wave function of the ground state has the form of a single determinant. Electronic absorption and vibrational (IR and resonance Raman) spectra of H2TTDPz and NiTTDPz were studied experimentally and simulated theoretically.

show abstract

“…In [ 20 ], we considered the question of the relationship between the scanning step Δs and the maximum value of the internuclear distance r, as well as the reliability of determining terms corresponding to large r values. It was shown that even when the scanning step Δs is reduced to 0.1 Å −1 , instead of the traditionally used 0.2 Å −1 or 0.25 Å −1 , the sensitivity of the GED method is very low for terms with internuclear distances r > 14 Å.…”

Section: Resultsmentioning

confidence: 99%

Cyclic Dimers of 4-n-Propyloxybenzoic Acid with Hydrogen Bonds in the Gaseous State

Giricheva

Bubnova

Krasnov

et al. 2022

IJMS

Self Cite

View full text Add to dashboard Cite

A comprehensive study of saturated vapors of 4-n-propyloxybenzoic acid (POBA) by gas electron diffraction (GED) and mass spectrometric (MS) methods supplemented by quantum chemical (QC) calculations was carried out for the first time. An attempt was made to detect dimeric forms of the acid in the gaseous state. It has been established that at the temperature of GED experiment, vapor over a solid sample contains up to 20 mol.% of cyclic dimers with two O-H...O hydrogen bonds. The main geometrical parameters of gaseous monomers and dimers of POBA are obtained. The distance r(O…O) = 2.574(12) Å in the cyclic fragment of the gaseous dimer is close to that in the crystal structure (2.611 Å). In the mass spectrum of the POBA recorded the ions of low intensity with a mass exceeding the molecular mass of the monomer were detected. The presence of ions, whose elemental composition corresponds to the dissociative ionization of the dimer, confirms the results of the GED experiment on the presence of POBA dimers in the gas state. The results of GED studies of acetic acid, benzoic acid, and POBA were compared. It is shown that the COOH fragment saves its geometric structure in monomers, as well as the COOH...HOOC fragment with two hydrogen bonds in dimers of different acids. The intermolecular interaction energy in considered acid dimers was estimated using QC calculations (B97D/6-311++G **). The significant value of last (>84 kJ/mol) is the reason for the noticeable presence of dimers in the gas phase.

show abstract

To the limit of gas-phase electron diffraction: Molecular structure of magnesium octa(m-trifluoromethylphenyl)porphyrazine

Cited by 19 publications

References 38 publications

Intramolecular London Dispersion Interaction Effects on Gas-Phase and Solid-State Structures of Diamondoid Dimers

Intramolecular London Dispersion Interaction Effects on Gas-Phase and Solid-State Structures of Diamondoid Dimers

Molecular Structure, Thermodynamic and Spectral Characteristics of Metal-Free and Nickel Complex of Tetrakis(1,2,5-thiadiazolo)porphyrazine

Cyclic Dimers of 4-n-Propyloxybenzoic Acid with Hydrogen Bonds in the Gaseous State

Contact Info

Product

Resources

About