Chalcogenides of the aminomethylphosphines derived from 1-methylpiperazine, 1-ethylpiperazine and morpholine: NMR, DFT and structural studies for determination of electronic and steric properties of the phosphines

Abstract

Chalcogenide derivatives of three aminomethylphosphines: P(CH2N(CH2CH2)2NCH3)3 (1), P(CH2N(CH2CH2)2NCH2CH3)3 (2) and P(CH2N(CH2CH2)2O)3 (3) were prepared: oxides--OP(CH2N(CH2CH2)2NCH3)3 (4), OP(CH2N(CH2CH2)2NCH2CH3)3 (5), OP(CH2N(CH2CH2)2O)3 (6), sulfides--SP(CH2N(CH2CH2)2NCH3)3 (7), SP(CH2N(CH2CH2)2NCH2CH3)3 (8), SP(CH2N(CH2CH2)2O)3 (9) and selenides--SeP(CH2N(CH2CH2)2NCH3)3 (10), SeP(CH2N(CH2CH2)2NCH2CH3)3 (11), SeP(CH2N(CH2CH2)2O)3 (12). The spectroscopic NMR analyses, DFT (B3LYP/6-31G**) calculations together with crystallographic studies of compounds 5, 6, 9 and 12 demonstrate that the structures and spectroscopic properties are strongly influenced by the chalcogen atom and not entirely contingent on aliphatic rings in the molecules. TEPs (Tolman's electronic parameters), estimated with DFT methods equal 2059.7 cm(-1) for 1, 2059.8 cm(-1) for 2 and 2061.2 cm(-1) for 3. These values are similar to TEPs estimated experimentally for other aminomethylphosphines. Phosphines 1, 2 and 3, despite very large Tolman cone angles show rather low influence of molecular geometry on their electronic properties: S4' (symmetric deformation coordinate) (59.8-64.8) and S4 (63.4-63.7) parameters are moderate. Suresh's steric effect (S(eff)) parameters for phosphines 1, 2 and 3 (2.70, 2.73 and 2.66, respectively) indicate minor electron-donating effect. Electronic effect (E(eff)) parameters (4.92, 5.21 and -0.40, respectively) can be easily modified by changing the substituents. 1J(SeP) coupling constants in the selenides are low (10: 707.5 11: 707.5 12: 709.8 Hz), but do not correlate with the TEP values in a way typical for aliphatic phosphines. The examined compounds do not show mutagenic properties and their potential toxicity is low, which is relevant in the context of their possible medical applications.

Biological activity and structure dependent properties of cuprous iodide complexes with phenanthrolines and water soluble tris (aminomethyl) phosphanes

“…Unlike the E eff and S eff parameters, the TEP (Tolman's electronic parameter [42]) captures the net electronic effects of the ligands. The TEP value estimated for 3 (2065.2 cm − 1 ) was in a good agreement with the experimental data (2063.0 cm − 1 in 5:1 THF (tetrahydrofuran)/H 2 O) [10] and it was slightly larger than those obtained for 2 (2061.8 cm − 1 ) and for 1 (2059.7 cm − 1 ) [40]. This indicates that 3 has the weakest electrondonating properties, which should result in the strongest bonds to be formed with electron rich metal atoms.…”

“…The values of E eff and S eff calculated for 3 were 0.85 and 2.74, respectively. A comparison with the respective values calculated for 1 (4.99 and 2.70) and 2 (− 0.40 and 2.66) [40] indicated that 3 displayed the strongest steric effect and a moderate electronic effect. Unlike the E eff and S eff parameters, the TEP (Tolman's electronic parameter [42]) captures the net electronic effects of the ligands.…”

“…2) for this compound. This parameter is a good indicator for the changes in the electron distribution in the phosphorus atom [30,40] during the coordination or chalcogenide formation processes. The S4 value for 3 (63.39) was close to the value calculated for 2 (63.40) and slightly smaller than the value for 1 (63.70).…”

“…Estimation of steric and electronic parameters for 3 was performed following the procedures described elsewhere [40].…”

2-N-Formilaminotiyofenol Bileşiğinin Spektroskopik Karakterizasyonu, Elektronik ve Çizgisel Olmayan Optik Özellikleri

“…Bu yöntemlerden Hatre-Fock (HF) ve Yoğunluk Fonksiyon Teorisi (DFT) literatürdeki birçok çalışmada moleküler özelliklerin etkin ve doğru bir şekilde değerlendirilmesi için kullanılmıştır (Burda et al, 2005;Yüksek et al, 2005a;Yüksek et al, 2005b;Starosta et al, 2010;Shokhmkar et al, 2014;Tamer et al, 2015a;Thanigaimani et al, 2015;Kazici et al, 2016;Preat et al, 2016 …”