An Ru-Substituted Tris(ethynyl)methyl Cation: Synthesis, Properties, and Structure of [{Cp(dppe)Ru(C≡C)}3C]PF6·C6H6

2020 ◽  
Vol 73 (6) ◽  
pp. 552
Author(s):  
Michael I. Bruce ◽  
Alexandre Burgun ◽  
Brian K. Nicholson ◽  
Natasha N. Zaitseva
Keyword(s):  
13C Nmr ◽  
Reduction Wave ◽  
Cyclic Voltammogram ◽  
Irreversible Oxidation ◽  
Synthesis Properties ◽  
Benzene Solvate ◽  
Dark Blue ◽  
Reversible Reduction ◽  
Methyl Cation

The dark blue complex [{Cp(dppe)Ru(C≡C)}3C]PF6 1 (Cp=cyclopentadienyl, dppe=1,2-bis(diphenylphosphino)ethane) was obtained in 46% yield by treatment of Ru(C≡CH)(dppe)Cp with CuCl/TMEDA (tetramethylethanediamine), followed by KOH and [NH4]PF6 in acetone; it was accompanied by known complexes {Cp(dppe)Ru}C≡CC≡C{Ru(dppe)Cp} 2 (22%) and yellow [1,3-{Cp(dppe)Ru}2C4H3]PF6 3 (2.6%). The structure of the cationic fragment of 1 in its benzene solvate consists of a central planar C attached to three C≡CRu(dppe)Cp fragments. The cation of 3 consists of a cyclobuten-1,3-diyl group bearing two Ru(dppe)Cp groups. The 13C NMR resonance of the central C in 1 is found at δ 66.11. The cyclic voltammogram of 1 contains three irreversible oxidation waves at +0.87, +0.79, and +0.25V, together with a reversible reduction wave at −1.38V (versus FeCp2/[FeCp2]+).

Eine elektrochemische und strukturelle Studie an den Eisensilylamiden Fe[N(SiMe3)2]2 und Fe[N(SiMe3)2]3 / An Electrochemical and Structural Study of the Iron Silylamides Fe[N(SiMe3)2]2 and Fe[N(SiMe3)2]3

2012 ◽  
Vol 67 (6) ◽  
pp. 549-556 ◽  
Author(s):  
Günter Margraf ◽  
Frauke Schödel ◽  
Inge Sänger ◽  
Michael Bolte ◽  
Matthias Wagner ◽  
...  
Keyword(s):  
Cyclic Voltammogram ◽  
X Ray Diffraction ◽  
Amido Complexes ◽  
X Ray ◽  
Redox Transition ◽  
Transfer Processes ◽  
Irreversible Oxidation ◽  
Reaction Solution ◽  
Reversible Redox ◽  
Electron Transfer Processes

The bis(trimethyl)silylamido complex Na(THF){Fe[N(SiMe3)2]3} and the disilane tBu3SiSitBu3 were obtained from the reaction of Fe[N(SiMe3)2]3 with the sodium silanide Na(THF)2[SitBu3] in a mixture of benzene and THF. Single crystals of Na(THF){Fe[N(SiMe3)2]3} suitable for X-ray diffraction were grown from the reaction solution at ambient temperature (orthorhombic, C2221, Z = 4). The solid-state structure features a contact-ion pair with two short N-Na contacts. The THF adducts {M(THF)2[N(SiMe3)2]2} reacted with 2,2´-bipyridine to give the corresponding complexes {M(2,2´bipy)[N(SiMe3)2]2} (M= Mn; Fe). Their structures (M= Fe: orthorhombic, Pca21, Z = 8; M = Mn: orthorhombic, Pbca, Z = 8) feature monomeric units. The cyclic voltammogram of Fe[N(SiMe3)2]3 revealed a reversible redox transition with the potential of -0;523 V (E½), which was assigned to the Fe(III)[N(SiMe3)2]3 → Fe(II)[N(SiMe3)2]-3 redox transition, whereas the compounds {Fe(THF)2[N(SiMe3)2]2} (Eox = -0;379 V) and {Fe(2,2´bipy)[N(SiMe3)2]2} (Eox = -0;436 V) featured irreversible oxidation waves. The related manganese bis(trimethylsilyl)amido complexes {Mn(THF)2[N(SiMe3)2]2} (Eox = -0;458 V) and {Mn(2,2´bipy)[N(SiMe3)2]2} (Eox = -0513 V) also underwent irreversibile electron transfer processes.

Syntheses, theoretical studies, and crystal structures of [Ni(II)SSRRL](PF6)2 and [Ni(II)SRSRL](Cl)(PF6) that contains anagostic interactions

2020 ◽  
pp. 1-10
Author(s):  
Peyton C. Bainbridge ◽  
Rudy L. Luck ◽  
Nick K. Newberry
Keyword(s):  
Theoretical Calculations ◽  
Structural Data ◽  
Theoretical Studies ◽  
Redox Potentials ◽  
X Ray ◽  
H Nmr ◽  
Irreversible Oxidation ◽  
Square Planar ◽  
Reduced Products ◽  
Reversible Reduction

The syntheses of two square planar nickel complexes containing the condensation and subsequently reduced products obtained by reacting [Ni(en)3](BF4)2 and acetone are reported. The complexes 5,5,7,12,12,14-hexamethyl-1(S),4(S),8(R),11(R)-tetraazacyclotetradecane-nickel(II)[PF6]2 and 5,5,7,12,12,14-hexamethyl-1(S),4(R),8(S),11(R)-tetraazacyclotetradecane-nickel(II)[Cl][PF6] labelled as [Ni(II)SSRRL](PF6)2 and [Ni(II)SRSRL](Cl)(PF6), respectively, were found to have slightly different solubilities that allowed for their purification. The complexes were characterized by FTIR, 1H NMR, and UV–vis spectra. Redox potentials, determined by cyclic voltammetry, established that [Ni(II)SSRRL](PF6)2 exhibits a reversible oxidation (E1/2(ox) = 0.85 V) and reduction (E1/2(red) = −1.59 V), whereas [Ni(II)SRSRL](Cl)(PF6) displays an irreversible oxidation (Epa(ox) = 1.37 V) and reversible reduction (E1/2(red) = −1.62 V) relative to the ferrocene couple at 0.0 V. Single crystal X-ray determinations established that one of the compounds, [Ni(II)SSRRL](PF6)2, contained two [Formula: see text] anions, whereas the other compound, [Ni(II)SRSRL](Cl)(PF6), contained one Cl− and one [Formula: see text] anion. In the solid state, compound [Ni(II)SSRRL](PF6)2 was held together by H-bonds between H atoms on the Ni containing dication and F atoms in the [Formula: see text] anion. Compound [Ni(II)SRSRL](Cl)(PF6) crystallized in the form of dimers held together by interactions between H atoms attached to N atoms on adjacent cations binding to two Cl− anions in the middle with these dimers held together by further H-bonding to interstitial [Formula: see text] anions. Complex [Ni(II)SRSRL](Cl)(PF6) was found to contain anagostic interactions on the bases of NMR (downfield shift in C–H protons) and structural data (2.3 < d(H-Ni) < 2.9 Å), as well as theoretical calculations.

Tris(2-thienyl)methyl cation; An unprecedent 13C NMR behavior

1986 ◽  
Vol 27 (46) ◽  
pp. 5657-5660 ◽  
Author(s):  
Belen Abarca ◽  
Gregorio Asensios ◽  
Rafael Ballesteros ◽  
Carmen Luna
Keyword(s):  
13C Nmr ◽  
Methyl Cation

The experimental determination of Th(iv)/Th(iii) redox potentials in organometallic thorium complexes

2019 ◽  
Vol 48 (29) ◽  
pp. 10782-10784 ◽  
Author(s):  
Christopher J. Inman ◽  
F. Geoffrey N. Cloke
Keyword(s):  
Experimental Determination ◽  
Reduction Wave ◽  
Cyclic Voltammogram ◽  
Redox Potentials

ThIV/ThIII reduction wave in the cyclic voltammogram of [Th(η-C5H3{SiMe3}2)3Cl].

scholarly journals Cyclic Methacrylate Tetrahydropyrimidinones: Synthesis, Properties, (Co)Polymerization

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 107
Author(s):  
Victor A. Gerasin ◽  
Marina V. Zhurina ◽  
Natalia A. Kleshcheva ◽  
Nikolai A. Sivov ◽  
Dmitry I. Mendeleev
Keyword(s):  
Radical Polymerization ◽  
13C Nmr ◽  
Salt Form ◽  
1H And 13C Nmr ◽  
Synthesis Conditions ◽  
Diallyldimethylammonium Chloride ◽  
Synthesis Properties ◽  
High Yields

During radical polymerization of novel biocidal methacrylate guanidine monomers, a cyclic byproduct was discovered and identified as 2-imino-5-methyltetrahydropyrimidin-4(1H)-one (THP). Its methacrylate salt (MTHP) was synthesized and characterized via 1H and 13C NMR and pyrolysis chromatography. Synthesis conditions of both THP and MTHP were optimized to high yields, and both MTHP homopolymerization (in aqua) and copolymerization with diallyldimethylammonium chloride (in aqua in salt form) were successfully carried out with middle to high yields, providing a promising platform for potential tailored biocide polymers.

Adsorptive cathodic stripping determination of minoxidil in pharmaceutical, cream and shampoo products

2011 ◽  
Vol 76 (5) ◽  
pp. 371-382 ◽  
Author(s):  
Farhad Ahmadi ◽  
Sahar Ghasemi ◽  
Mehdi Rahimi-Nasrabadi
Keyword(s):  
Supporting Electrolyte ◽  
Pulse Height ◽  
Direct Determination ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Reduction Wave ◽  
Cyclic Voltammogram ◽  
Topical Solution ◽  
Cathodic Stripping

The cyclic voltammetric behavior of minoxidil was studied in a buffer with pH 3. Contradictory to that mentioned in a previously published work, the cyclic voltammogram of minoxidil exhibited a single 2-electron irreversible reduction wave in a buffer with pH 3. This wave was attributed to the reduction of the N→O bond. The cathodic differential pulse wave height decreased on the increase of pH till it disappeared in solution with pH 7.2. The quantitative trace determination of minoxidil was studied at a hanging mercury drop electrode by adsorptive cathodic stripping voltammetry. A fully validated sensitive procedure based on controlled adsorptive accumulation of the drug onto a HMDE was developed for its direct determination. Accumulation of minoxidil was found to be optimized in 0.1 M Britton–Robinson buffer with pH 2.0 as supporting electrolyte under the following conditions: accumulation potential –0.2 V, accumulation time 40 s, scan rate 40 mV s–1 and pulse height 50 mV. The proposed procedure was applied successfully for determination of minoxidil in its topical solution and illegal shampoo and cream. The mean recoveries of the minoxidil were 99.8, 97.8 and 96.7% and with RSD of 0.86, 1.24 and 1.89% in pharmaceutical topical solution, shampoo and cream, respectively.

ChemInform Abstract: Synthesis, Properties and1H-,13C-NMR Spectra of Functional 1-Adamantylgermane Derivatives.

1986 ◽  
Vol 17 (13) ◽  
Author(s):  
O. N. CHERNYSHEVA ◽  
T. K. GAR ◽  
A. V. KISIN ◽  
F. V. MIRONOV
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectra ◽  
Synthesis Properties

A cooperative computational and experimental investigation on electrochemical behavior of metoprolol and its voltammetric determination

2013 ◽  
Vol 91 (10) ◽  
pp. 951-959 ◽  
Author(s):  
Seraceddin Levent Zorluoğlu ◽  
İbrahim Hüdai Taşdemir ◽  
Abdulilah Ece ◽  
Esma Kiliç
Keyword(s):  
Electrochemical Behavior ◽  
Phenyl Ring ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
Serum Samples ◽  
Irreversible Oxidation ◽  
Relative Standard ◽  
Homo And Lumo ◽  
Voltammetric Methods ◽  
Reversible Reduction

The electrochemical behavior of metoprolol (MTP) was studied via experimental and computational approaches. Theoretical calculations were performed at the B3LYP/6-31+G(d)//AM1 level whereas experimental studies were carried out on a hanging mercury drop electrode (HMDE) and glassy carbon electrode (GCE). According to the computational results, both HOMO and LUMO of MTP were located at the phenyl ring. Hence, oxidation and reduction are expected to take place at the phenyl ring. Experimental studies on HMDE were based on reversible reduction at approximately –1.4 V and studies on GCE were based on irreversible oxidation at approximately 0.9 V versus Ag/AgCl (3 mol L−1 KCl) in Britton−Robinson buffer. Voltammetric methods with and without adsorptive stripping modes were developed. Proposed methods were successfully applied to tablet solutions and spiked human serum samples. Results are satisfactory with recovery values between 94.5% and 102.5% and a relative standard deviation lower than 6%.

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