Electronegativity and chemical hardness of organoelement groups

Peregudov, Аlexander S.; Kravtsov, D. N.

doi:10.1002/1099-0739(200101)15:1<27::aid-aoc119>3.0.co;2-m

Cited by 3 publications

(2 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The methodology of group electronegativity, hardness, and softness can indeed be applied to tin compounds without any fundamental changes, as relativistic effects may still be expected to be relatively small and probably are canceled out in the evaluation of these quantities which is no longer the case for fifth and higher row elements. Peregudov and his group have done studies on this kind of compound, [44][45][46][47][48][49] their approach being, however, less in line with our previous contributions and concentrating on large groups.…”

Section: Introductionmentioning

confidence: 99%

DFT Calculations of ¹¹⁹Sn Chemical Shifts Using Gauge-Including Atomic Orbitals and Their Interpretation via Group Properties

et al. 2002

View full text Add to dashboard Cite

Nonrelativistic DFT calculations of the 119 Sn chemical shift are presented for a large series of tetracoordinated Sn compounds, of the type CH 3 SnRR′R′′, where R, R′, R′′ are halogens, alkyl, halogenated alkyl, alkoxy, or alkyl thio groups. The B3PW91 functional is used in conjunction with the IGLO III basis set. Leaving out compounds associating in solution and thus changing the Sn coordination, a correlation coefficient r 2 of 0.978 ( 0.023 is obtained between solvent NMR shifts and calculated values, with a slope of 0.984. These results indicate that this methodology yields excellent results both in the absolute and relative sense for the majority of the cases studied, where cancellation of errors (solvent and relativistic effects) occurs. The results were interpreted in terms of calculated electronegativity, hardness, and softness of the groups SnRR′R′′, applying a methodology previously developed by us (J. Phys. Chem. 1993, 97, 1826) and using the 6-311++G** basis set for H, C, Cl, Br, O, and S and 3-21G for Sn and I. Sequences of group electronegativities and hardnesses could be rationalized via previously calculated or experimental first and second row atomic or functional group values reflecting the interplay of qualitative and quantitative changes in groups on the central Sn atom. The evolution of the 119 Sn chemical shift can be successfully interpreted on the basis of group electronegativities for groups introduced in the β position of the Sn atom, whereas changes in R position (i.e., groups directly bonded to Sn) turn out to be essentially hardness related, especially when changes in the row of the periodic table are involved.

show abstract

Section: Introductionmentioning

confidence: 99%

DFT Calculations of ¹¹⁹Sn Chemical Shifts Using Gauge-Including Atomic Orbitals and Their Interpretation via Group Properties

et al. 2002

View full text Add to dashboard Cite

show abstract

“…In accordance with [4], the electronegativity of the Cp(CO) 2 Fe fragment is appreciably lower than that of Cp(CO) 3 Mo. This may be one of the factors responsible for the~140 times higher rate constant of oxidation of Cd with I in DMF at 293 K, compared to that of the reaction of Cp(CO) 3 MoCl with Cd under identical conditions [5].…”

mentioning

confidence: 99%

Oxidation of Cadmium with Dicarbonylcyclopentadienyliron Chloride in Dimethylformamide

et al. 2005

View full text Add to dashboard Cite

The kinetic and activation parameters of oxidation of cadmium with dicarbonylcyclopentadienyliron chloride in dimethylformamide were determined. The apparent equilibrium constants, enthalpy, and entropy of adsorption of the reactants on the metal surface were evaluated. The reaction scheme was suggested.In [1] we reported on the synthesis of an organometallic compound with a Mg3Fe bond by oxidation of Mg with dicarbonylcyclopentadienyliron chloride (I). In this study we examined the kinetics and products of the reaction of I with Cd.The dependences of the reaction rate on the content of I and dimethylformamide (DMF, used as solvent) in the reaction mixture are shown in Figs. 1 and 2. The curves shown in Figs. 1 and 2 do not allow unambiguous conclusion on whether the adsorption centers on the metal surface are similar or different in nature. Therefore, we studied the dependences of the reaction rate on the concentration of I at different fixed concentrations of DMF in the reaction mixture (Fig. 3). The results, in line with the concept presented in [2], suggest that both compound I and DMF are adsorbed on reaction centers of similar nature on the Cd surface. In this case, the reaction course can be described by the scheme Ox + S %%$ "%% OxS,The expression for the reaction rate is as follows:where k`= k(S 0 ) 2 , k is the rate constant, S 0 is the number of active centers on unit surface area of the metal, and K Ox ads and K L ads are the equilibrium constants of adsorption of the oxidant and ligand, respectively.Treatment of the experimental data in the coordinates (C Ox /V) 1/2 = f (C Ox ) at C L = const and (C L /V) 1/2 = f (C L ) at C Ox = const allowed calculation of the apparent equilibrium constants of adsorption of I and DMF and the reaction rate constants: T, K 278 288 293 K Ox ads 14.59 7.11 5.55 K L ads 0.25 0.19 0.16 k 10 2 , g cm !2 min !1 1.17 4.65 5.70From the temperature dependences of these quantities, we determined the apparent enthalpy and entropy of adsorption of the reactants on the metal surface: DH Ox ads 352 + 4 kJ mol !1 , DS Ox ads 3164 + 12 J mol !1 K !1 , DH L ads 321 + 2 kJ mol !1 , DS L ads 399 + 9 J mol !1 K !1 , and activation energy of the process E 75 + 5 kJ mol !1 .

show abstract

Synthesis of Bis( ⁵-cyclopentadienyldicarbonyliron)stannane Dichloride by Direct Oxidation of Tin and Reaction of This Compound and Its Analogs with Magnesium

Maslennikov¹,

Tsarev²,

Spirina³

et al. 2004

Russian Journal of General Chemistry

View full text Add to dashboard Cite

Electronegativity and chemical hardness of organoelement groups

Cited by 3 publications

References 55 publications

DFT Calculations of ¹¹⁹Sn Chemical Shifts Using Gauge-Including Atomic Orbitals and Their Interpretation via Group Properties

DFT Calculations of ¹¹⁹Sn Chemical Shifts Using Gauge-Including Atomic Orbitals and Their Interpretation via Group Properties

Oxidation of Cadmium with Dicarbonylcyclopentadienyliron Chloride in Dimethylformamide

Synthesis of Bis( ⁵-cyclopentadienyldicarbonyliron)stannane Dichloride by Direct Oxidation of Tin and Reaction of This Compound and Its Analogs with Magnesium

Contact Info

Product

Resources

About

Electronegativity and chemical hardness of organoelement groups

Cited by 3 publications

References 55 publications

DFT Calculations of 119Sn Chemical Shifts Using Gauge-Including Atomic Orbitals and Their Interpretation via Group Properties

DFT Calculations of 119Sn Chemical Shifts Using Gauge-Including Atomic Orbitals and Their Interpretation via Group Properties

Oxidation of Cadmium with Dicarbonylcyclopentadienyliron Chloride in Dimethylformamide

Synthesis of Bis( 5-cyclopentadienyldicarbonyliron)stannane Dichloride by Direct Oxidation of Tin and Reaction of This Compound and Its Analogs with Magnesium

Contact Info

Product

Resources

About

DFT Calculations of ¹¹⁹Sn Chemical Shifts Using Gauge-Including Atomic Orbitals and Their Interpretation via Group Properties

DFT Calculations of ¹¹⁹Sn Chemical Shifts Using Gauge-Including Atomic Orbitals and Their Interpretation via Group Properties

Synthesis of Bis( ⁵-cyclopentadienyldicarbonyliron)stannane Dichloride by Direct Oxidation of Tin and Reaction of This Compound and Its Analogs with Magnesium