Synthesis and structure of 1,5-diaza-3,7-diphosphacyclooctanes

Arbuzöv, B. A.; Erastov, O. A.; Nikonov, G. N.; Arshinova, R. P.; Romanova, I. P.; Kadyrov, Renat

doi:10.1007/bf00954289

Cited by 10 publications

(8 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Phenylphosphine (Strem, 99%) paraformaldehyde (Aldrich, 95%), diethyl para- aminobenzylphosphonate (Acros, 98%), and para- trifluoromethylaniline (Aldrich, 99%) were used as received; para- anisidine (Aldrich 99%) was sublimed before use. [Ni(MeCN) 6 ](BF 4 ) 2 ]·1/2 MeCN, P Ph 2 N C6H4Br 2 , and P Ph 2 N C6H4Me 2 were prepared using literature methods …”

Section: Methodsmentioning

confidence: 99%

[Ni(P^Ph₂N^C6H4X₂)₂]²⁺ Complexes as Electrocatalysts for H₂ Production: Effect of Substituents, Acids, and Water on Catalytic Rates

et al. 2011

View full text Add to dashboard Cite

A series of mononuclear nickel(II) bis(diphosphine) complexes [Ni(P(Ph)(2)N(C6H4X)(2))(2)](BF(4))(2) (P(Ph)(2)N(C6H4X)(2) = 1,5-di(para-X-phenyl)-3,7-diphenyl-1,5-diaza-3,7-diphosphacyclooctane; X = OMe, Me, CH(2)P(O)(OEt)(2), Br, and CF(3)) have been synthesized and characterized. X-ray diffraction studies reveal that [Ni(P(Ph)(2)N(C6H4Me)(2))(2)](BF(4))(2) and [Ni(P(Ph)(2)N(C6H4OMe)(2))(2)](BF(4))(2) are tetracoordinate with distorted square planar geometries. The Ni(II/I) and Ni(I/0) redox couples of each complex are electrochemically reversible in acetonitrile with potentials that are increasingly cathodic as the electron-donating character of X is increased. Each of these complexes is an efficient electrocatalyst for hydrogen production at the potential of the Ni(II/I) couple. The catalytic rates generally increase as the electron-donating character of X is decreased, and this electronic effect results in the favorable but unusual situation of obtaining higher catalytic rates as overpotentials are decreased. Catalytic studies using acids with a range of pK(a) values reveal that turnover frequencies do not correlate with substrate acid pK(a) values but are highly dependent on the acid structure, with this effect being related to substrate size. Addition of water is shown to dramatically increase catalytic rates for all catalysts. With [Ni(P(Ph)(2)N(C6H4CH2P(O)(OEt)2)(2))(2)](BF(4))(2) using [(DMF)H](+)OTf(-) as the acid and with added water, a turnover frequency of 1850 s(-1) was obtained.

show abstract

Section: Methodsmentioning

confidence: 99%

[Ni(P^Ph₂N^C6H4X₂)₂]²⁺ Complexes as Electrocatalysts for H₂ Production: Effect of Substituents, Acids, and Water on Catalytic Rates

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Compound 19 : Solid NiCl 2 (0.05 g, 0.38 mmol) was added to a solution of 1,3,5,7‐tetraphenyl‐1,5‐diaza‐3,7‐diphosphacyclooctane32a, b (0.35 g, 0.77 mmol) in DMF (20 mL) and the mixture was stirred for 24 h. The solvent was evaporated under reduced pressure, then the resultant dark‐red powder was washed with ethanol (20 mL), and dried under reduced pressure to give 19 (0.31 g, 79 %). Single crystals of 19 suitable for X‐ray crystal‐structure analysis were obtained by slow evaporation of a solution of 19 in chloroform.…”

Section: Methodsmentioning

confidence: 99%

New Functional Cyclic Aminomethylphosphine Ligands for the Construction of Catalysts for Electrochemical Hydrogen Transformations

Musina

Khrizanforova

Strelnik

et al. 2014

Chemistry A European J

View full text Add to dashboard Cite

Eight-membered cyclic functional bisphosphines, namely 1,5-di-aryl-3,7-di(2-pyridyl)-1,5-diaza-3,7-diphosphacyclooctanes (aryl=2-pyridyl, m-tolyl, p-tolyl, diphenylmethyl, benzyl, (R)-(+)-(α-methyl)benzyl), with 2-pyridyl substituents on the phosphorus atoms have been synthesized by condensation of 2-pyridylphosphine, formaldehyde, and the corresponding primary amine. The structures of some of these bisphosphines have been investigated by X-ray crystallography. The bisphosphines readily form neutral P,P-chelate complexes [(κ(2)-P,P-L)MCl2], cationic bis-P,P-chelate complexes [(κ(2)-P,P-L)2 M](2+), or a five-coordinate complex [(κ(2)-P,P-L)2 NiBr]Br. The electrochemical behavior of two of the nickel complexes, and their catalytic activities in electrochemical hydrogen evolution and hydrogen oxidation, including the fuel-cell test, have been studied.

show abstract

“…Hence, an almost ideal crown was found in 1,3,5,7-tetraphenyl-1,5,3,7-diazadiphosphocane with two trivalent phosphorus atoms on the opposite ends of the eightmembered ring [4]. This molecule preserves the same conformation in benzene solutions [5], unlike the corresponding derivative of four-coordinate phosphorus [5] that has the distorted boat!boat conformation in crystal (according to X-ray data) and prefers the crown conformation in solution. The preferred conformation of the eight-membered heteroring in 1,3,6,2-dioxaphosphasilocanes, as found by high-resolution NMR spectroscopy, dipole moment and Kerr effect measurements, and semiempirical quantumchemical calculations, is crown independently of the coordination of the phosphorus atom (3 or 4) [6].…”

mentioning

confidence: 95%

“…Prerequisite for such interactions is that the heteroring conformation allows proximity of the heteroatoms to each other. Fairly scarce data are available in the literature, concerning the structure of 1,3,2-dioxaphosphocanes [133] or diphosphocanes with P3C bonds [4,5]. Hence, an almost ideal crown was found in 1,3,5,7-tetraphenyl-1,5,3,7-diazadiphosphocane with two trivalent phosphorus atoms on the opposite ends of the eightmembered ring [4].…”

mentioning

confidence: 99%

Conformational analysis of 1,3,6,2-dioxazaphosphocanes and 1,3,6,2-dioxazasilocanes

et al. 2004

View full text Add to dashboard Cite

The steric structure of 1,3,6,2-dioxazaphosphocanes and 1,3,6,2-dioxazasilocanes in solution was established by high-resolution 1 H, 13 C, and 31 P NMR spectroscopy and PM3 calculations. It is shown that the preferred conformation of the eight-membered heterocycle is chair!chair (crown).The structure of eight-membered heterocycles containing both electron-donor and electron-acceptor centers attracts researcher's attention because, together with solving conformational problems (ring conformation, orientation of exocyclic substituents), one can expect to reveal transannular intramolecular interactions in these compounds. Prerequisite for such interactions is that the heteroring conformation allows proximity of the heteroatoms to each other. Fairly scarce data are available in the literature, concerning the structure of 1,3,2-dioxaphosphocanes [133] or diphosphocanes with P3C bonds [4,5]. Hence, an almost ideal crown was found in 1,3,5,7-tetraphenyl-1,5,3,7-diazadiphosphocane with two trivalent phosphorus atoms on the opposite ends of the eightmembered ring [4]. This molecule preserves the same conformation in benzene solutions [5], unlike the corresponding derivative of four-coordinate phosphorus [5] that has the distorted boat!boat conformation in crystal (according to X-ray data) and prefers the crown conformation in solution. The preferred conformation of the eight-membered heteroring in 1,3,6,2-dioxaphosphasilocanes, as found by high-resolution NMR spectroscopy, dipole moment and Kerr effect measurements, and semiempirical quantumchemical calculations, is crown independently of the coordination of the phosphorus atom (3 or 4) [6]. The X-ray analysis of one of these molecules with an exocyclic P=Se bond, too, established that the eightmembered P,Si-containing heteroring has the crown conformation of [7]. However, MeN(CH 2 CH 3 O) 2 . ÄÄÄÄÄÄÄÄÄÄÄÄ K Deceased.

show abstract

Synthesis and structure of 1,5-diaza-3,7-diphosphacyclooctanes

Cited by 10 publications

References 3 publications

[Ni(P^Ph₂N^C6H4X₂)₂]²⁺ Complexes as Electrocatalysts for H₂ Production: Effect of Substituents, Acids, and Water on Catalytic Rates

[Ni(P^Ph₂N^C6H4X₂)₂]²⁺ Complexes as Electrocatalysts for H₂ Production: Effect of Substituents, Acids, and Water on Catalytic Rates

New Functional Cyclic Aminomethylphosphine Ligands for the Construction of Catalysts for Electrochemical Hydrogen Transformations

Conformational analysis of 1,3,6,2-dioxazaphosphocanes and 1,3,6,2-dioxazasilocanes

Contact Info

Product

Resources

About

Synthesis and structure of 1,5-diaza-3,7-diphosphacyclooctanes

Cited by 10 publications

References 3 publications

[Ni(PPh2NC6H4X2)2]2+ Complexes as Electrocatalysts for H2 Production: Effect of Substituents, Acids, and Water on Catalytic Rates

[Ni(PPh2NC6H4X2)2]2+ Complexes as Electrocatalysts for H2 Production: Effect of Substituents, Acids, and Water on Catalytic Rates

New Functional Cyclic Aminomethylphosphine Ligands for the Construction of Catalysts for Electrochemical Hydrogen Transformations

Conformational analysis of 1,3,6,2-dioxazaphosphocanes and 1,3,6,2-dioxazasilocanes

Contact Info

Product

Resources

About

[Ni(P^Ph₂N^C6H4X₂)₂]²⁺ Complexes as Electrocatalysts for H₂ Production: Effect of Substituents, Acids, and Water on Catalytic Rates

[Ni(P^Ph₂N^C6H4X₂)₂]²⁺ Complexes as Electrocatalysts for H₂ Production: Effect of Substituents, Acids, and Water on Catalytic Rates