Übergangsmetallkomplexe mit Schwefelliganden, XIII* Synthesen und Reaktionen der 1,2-Benzoldithiolatomolybdat-Komplexe [MO(C6H4S2)3]n- (n = 0, 1, 2) und des Hydrid-Komplexes [Mo(H)(C6H4S2)3]3- / Transition Metal Complexes with Sulfur Ligands, XIII* Syntheses and Reactions of the 1,2-Benzenedithiolato Molybdate Complexes [MO(C6H4S2)3]n- - (n = 0 , 1, 2 ) and the Hydride Complex [Mo(H)(C6H4S2)3]3-

1985 ◽  
Vol 40 (3) ◽  
pp. 380-388 ◽  
Author(s):  
Dieter Sellmann ◽  
Lothar Zapf
Keyword(s):  
Nmr Spectroscopy ◽  
Transition Metal Complexes ◽  
Metal Hydride ◽  
Complex Salt ◽  
Alkyl Halides ◽  
Molar Ratio ◽  
Substitution Reactions ◽  
Hydride Complex ◽  
H Nmr ◽  
First Time

Modes of formation as well as redox and substitution reactions of the 1,2-benzenedithiolate complexes [Mo(C6H4S2)3]n- (n = 0, 1, 2, (3)) are described. [MoCl4(THF)2] with neutral C6H4(SH)2 gives the Mo(VI) complex [Mo(C6H4S2)3]; with C6H4S22-, however, the Mo(IV) complex [Mo(C6H4S2)3]2- can be isolated as the PPh4+ or NR4+ salt; in the course of the synthesis of (NMe4)2[Mo(C6H4S2)3] in MeOH/THF, the complex salt trans-(NMe4)2[Mo(C6H4S2)2(OCH3)2] is also obtained. Directly and controlled by pH, [Mo(VI)(C6H4S2)3] can be reduced by NaOH/MeOH to afford [Mo(V)(C6H4S2)3]- or [Mo(IV)(C6H4S2)3]2-. [Mo(VI)(C6H4S2)3] and (NMe4)2[Mo(IV)(C6H4S2)3] symproportionate in MeOH to yield (NMe4)[Mo(V)(C6H4S2)3] , which was isolated for the first time. When butyllithium reacts with [Mo(VI)(C6H4S2)3] in the molar ratio of 1:1, 2 :1 or 3:1, one obtains the Mo(V), Mo(IV) dithiolates or an orange complex, respectively. The latter is extremely H2O - as well as O2-sensitive; it is identified by its reactions with H2O , ROH, O2 , alkyl halides and NO as well as by 1H NMR spectroscopy as a salt containing the [MO(H)(C6H4S2)3]3- anion. [Mo(H)(C6H4S2)3]3- is the first example of an exclusively sulfur coordinated metal hydride complex. With NO it reacts in several steps yielding first N2O and [Mo(IV)(C6H4S2)3]2-; subsequently the Mo(IV) complex is reductively nitrosylated by further NO yielding cis-[Mo(NO)2(C6H4S2)2]2-, which is isolated as NMe4+ salt.

One-pot synthesis of the new Hydroxamic acid and its complexes with metals

2022 ◽  
Vol 19 ◽  
Author(s):  
Gulu Abbasova ◽  
Ajdar Medjidov
Keyword(s):  
Nmr Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Hydroxamic Acid ◽  
Uv Spectroscopy ◽  
Molar Ratio ◽  
One Pot ◽  
Ethanol Medium ◽  
Physicochemical Methods ◽  
Colored Complexes ◽  
First Time

Abstract: A one-pot conversion of 2-hydroxy-1-naphthoic aldehyde to hydroxamic acid was described. An efficient photoorganocatalytic method of synthesis was developed. The obtained hydroxamic acid was identified by various physicochemical methods such as IR, UV- and NMR-spectroscopy. Solid colored complexes of copper (II) and iron (II), respectively, green and brown colours with the obtained hydroxamic acid were synthesized in ethanol medium for the first time. The molar ratio of ligand and metal in the complex was 2:1. Their structures were established using IR, UV- spectroscopy and thermogravimetric analysis.

Gehinderte Ligandbewegungen in Übergangsmetallkomplexen, XXXI [1]. Synthese und Dynamik von Acetyl-carbonyl-η5-cyclopentadienyl-η4-dien-wolfram-Komplexen / Hindered Ligand Movements in Transition Metal Complexes, XXXI [1]. Syntheses and Dynamics of Acetyl-carbonyl-η5-cyclopentadienyl-η4-diene-tungsten Complexes

1986 ◽  
Vol 41 (5) ◽  
pp. 599-605 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Kurt Nist ◽  
Joachim Kögler
Keyword(s):  
Nmr Spectroscopy ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Conjugated Dienes ◽  
The Other ◽  
Molecular Plane ◽  
H Nmr ◽  
Tungsten Complexes ◽  
Diene Ligands

Tricarbonyl-η5-cyclopentadienyl-methyl-tungsten (1) reacts upon UV irradiation with conjugated dienes, like 1,3-butadiene (2), E-1,3-pentadiene (3), 2-methyl-1,3-butadiene (4), 2,3-dimethyl-1,3- butadiene (5), 1,3-cyclopentadiene (6) and 1,3-cyclohexadiene (7), to give the corresponding, quasisquare- pyramidal [(η5-C5H5)W(CO)(COCH3)(η4-diene)] complexes (8-13). With the unsymmetrically substituted dienes 3 and 4, only one of the possible diastereotopic complexes are obtained. At 200 to 230 K, 8-12 show two isomers, which are distinguished by the orientations (o or u) of the diene with respect to the other ligands. The interconversion of the o- and u-isomers was studied by dynamic 1H NMR spectroscopy and is explained by an intramolecular ±180° rotation of the diene ligands in the molecular plane. The barriers o f activation ⊿G* 300 are between 57.8 and 61.0 ± 1 kJ/mol.

Isolierungen und 11C-NMR-Spektroskopie von Indoleninalkaloiden / Isolation and 13C NMR Spectroscopy of Indolenine Alkaloids

1982 ◽  
Vol 37 (4) ◽  
pp. 494-498 ◽  
Author(s):  
Mohammad Ataullah Khan ◽  
Hans Horn ◽  
Wolfgang Voelter
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Nmr Spectra ◽  
13C Nmr Spectroscopy ◽  
H Nmr ◽  
First Time

The indolenine alkaloids raucaffricine and perakine were isolated from Rauwolfia caffra Sonder and their PFT 13C{1H}-NMR spectra studied for the first time. The interpretations of their spectra were accomplished in correlating with those of quinuclidine, indole, methyl-α-D-galactopyranoside, methyl-β-D-galactopyranoside, methyl-2,6-di-O-methyl-α-D-galactopyranoside and methyl-3-O-methyl-β-D-galactopyranoside.

Carbon versus oxygen nucleophilic selectivity in the reaction of the aryloxide ions, 2,6- and 3,5-di-tert-butylphenoxide, with the 2-[(nitro)\dn6 xaryl]-4,6-dinitrobenzotriazole 1-oxide series of super-electrophiles. Stereoelectronic factors on C-7 Meisenheimer complex formation versus C-1' SNAr displacement

1998 ◽  
Vol 76 (6) ◽  
pp. 662-671 ◽  
Author(s):  
Julian M Dust ◽  
Richard A Manderville
Keyword(s):  
Nmr Spectroscopy ◽  
Nucleophilic Aromatic Substitution ◽  
Nucleophilic Attack ◽  
Aromatic Substitution ◽  
Factors Affecting ◽  
H Nmr ◽  
Sterically Demanding ◽  
Biphenyl Derivative ◽  
First Time ◽  
Electrophilic Site

The 2-[(nitro)xaryl]-4,6-dinitrobenzotriazole 1-oxides (1, Pi-DNBT (x = 3); 2, DNP-DNBT (x = 2); 3, NP-DNBT (x = 1)) are electron-deficient nitro-substituted heteroaromatic substrates that possess two sites for nucleophilic attachment: C-7 and C-1'. Generally, attack at the super-electrophilic C-7 site yields spectroscopically observable anionic sigma -bonded adducts, whereas attack at C-1' leads to displacement products in an overall process of nucleophilic aromatic substitution (SNAr). To gain an understanding of the factors affecting C-1' versus C-7 attack by potentially ambident aryloxide (C- and O-)nucleophiles, we have monitored the reactions of 1-3 with 2,6-di-tert-butylphenoxide (2,6-ArO-) and 3,5-di-tert-butylphenoxide (3,5-ArO-) using 400 MHz 1H NMR spectroscopy (deuterated dimethyl sulfoxide solvent at ambient temperature). The results indicate that 2,6-ArO- acts only as a C-nucleophile with O-attack precluded, presumably by the sterically demanding tert-butyl groups flanking the O-nucleophilic centre. Although 2,6-ArO- reacts preferentially at C-7 of 1-3, the biphenyl derivative that arises from C-1' attack is also observed with 1, the first time that C-nucleophilic attack has been seen at this electrophilic site. In contrast, 3,5-ArO- acts only as an O-nucleophile, also as a consequence of the steric hindrance to the C-4 position; this aryloxide reacts entirely at C-1' of Pi-DNBT but also exclusively at C-7 of 3. However, with DNP-DNBT, 2, both the C-7 O-adduct and C-1' displacement products are noted; attack at C-1' is dominant. The selectivity (C-7 versus C-1') found in these reactions is discussed with emphasis given to stereoelectronic factors that may stabilize the putative C-1' O-adducts.Key words: aryloxides, super-electrophiles, Meisenheimer complexes, 2-[(nitro)xaryl]-4,6-dinitrobenzotriazole 1-oxides.

scholarly journals Synthesis, characterization and crystal structures of the bidentate Schiff baseN,N′-bis(2-nitrocinnamaldehyde)ethylenediamine and its complex with CuNCS and triphenylphosphane

2015 ◽  
Vol 71 (7) ◽  
pp. 578-583 ◽  
Author(s):  
William Clegg ◽  
Ross W. Harrington ◽  
Kazem Barati ◽  
Mohammad Hossein Habibi ◽  
Morteza Montazerozohori ◽  
...  
Keyword(s):  
Schiff Base ◽  
Nmr Spectroscopy ◽  
Nitro Group ◽  
Bidentate Ligand ◽  
Molar Ratio ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Bite Angle ◽  
Elemental Analyses

Reaction of copper(I) thiocyanate and triphenylphosphane with the bidentate Schiff baseN,N′-bis(trans-2-nitrocinnamaldehyde)ethylenediamine {Nca2en, (1); systematic name (1E,1′E,2E,2′E)-N,N′-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]}, C20H18N4O4, in a 1:1:1 molar ratio in acetonitrile resulted in the formation of the complex {(1E,1′E,2E,2′E)-N,N′-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]-κ2N,N′}(thiocyanato-κN)(triphenylphosphane-κP)copper(I)], [Cu(NCS)(C20H18N4O4)(C18H15P)] or [Cu(NCS)(Nca2en)(PPh3)], (2). The Schiff base and copper(I) complex have been characterized by elemental analyses, IR, electronic and1H NMR spectroscopy, and X-ray crystallography [from synchrotron data for (1)]. The molecule of (1) lies on a crystallographic inversion centre, with atransconformation for the ethylenediamine unit, and displays significant twists from coplanarity of its nitro group, aromatic ring, conjugated chain and especially ethylenediamine segments. It acts as a bidentate ligand coordinatingviathe imine N atoms to the CuIatom in complex (2), in which the ethylenediamine unit necessarily adopts a somewhat flattenedgaucheconformation, resulting in a rather bowed shape overall for the ligand. The NCS−ligand is coordinated through its N atom. The geometry around the CuIatom is distorted tetrahedral, with a small N—Cu—N bite angle of 81.56 (12)° and an enlarged opposite angle of 117.29 (9)° for SCN—Cu—P. Comparisons are made with the analogous Schiff base having no nitro substituents and with metal complexes of both ligands.

Divalent Transition Metal Complexes of Potentially Polynucleating 8-Hydroxyquinoline-5-sulfonyl Hydrazone

1994 ◽  
Vol 59 (8) ◽  
pp. 1800-1808
Author(s):  
Said A. Ibrahim ◽  
Sahar A. El-Gyar ◽  
Aly A. Abdel-Hafez ◽  
Mostafa K. Rabia
Keyword(s):  
Antimicrobial Activity ◽  
Nmr Spectroscopy ◽  
Transition Metal Complexes ◽  
Elemental Analysis ◽  
Metal Ion ◽  
Free Ligand ◽  
Chelating Agent ◽  
Conductivity Measurements ◽  
H Nmr ◽  
Trinuclear Complexes

The Co(II), Ni(II), Cu(II) and Zn(II) complexes with 8-hydroxyquinoline-5-sulfonylhydrazone are described. It has been found that the ligand can coordinate to metal ion as a monobasic bidentate chelating agent and it can form di- and trinuclear complexes while acting as a dibasic tetradentate one. The structure of the isolated complexes have been suggested on the basis of elemental analysis, IR, 1H NMR spectroscopy and conductivity measurements. The complexes are all formulated as four-coordinate. Some complexes showed enhanced antimicrobial activity relative to the free ligand.

scholarly journals NMR Spectroscopy of Human Eye Tissues: A New Insight into Ocular Biochemistry

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Tomasz Kryczka ◽  
Edward Wylęgała ◽  
Dariusz Dobrowolski ◽  
Anna Midelfart
Keyword(s):  
Nmr Spectroscopy ◽  
Human Eye ◽  
H Nmr ◽  
Biochemical Compounds ◽  
Eye Tissues ◽  
Metabolic Properties ◽  
Human Eyes ◽  
First Time ◽  
Insight Into ◽  
Complex Organ

Background. The human eye is a complex organ whose anatomy and functions has been described very well to date. Unfortunately, the knowledge of the biochemistry and metabolic properties of eye tissues varies. Our objective was to reveal the biochemical differences between main tissue components of human eyes.Methods. Corneas, irises, ciliary bodies, lenses, and retinas were obtained from cadaver globes 0-1/2 hours postmortem of 6 male donors (age: 44–61 years). The metabolic profile of tissues was investigated with HR MAS1H NMR spectroscopy.Results. A total of 29 metabolites were assigned in the NMR spectra of the eye tissues. Significant differences between tissues were revealed in contents of the most distant eye-tissues, while irises and ciliary bodies showed minimal biochemical differences. ATP, acetate, choline, glutamate, lactate, myoinositol, and taurine were identified as the primary biochemical compounds responsible for differentiation of the eye tissues.Conclusions. In this study we showed for the first time the results of the analysis of the main human eye tissues with NMR spectroscopy. The biochemical contents of the selected tissues seemed to correspond to their primary anatomical and functional attributes, the way of the delivery of the nutrients, and the location of the tissues in the eye.

scholarly journals The New μ-Phenylvinylidene RePt Complexes Containing Platinum-Bound 1-(Isocyanomethylsulfonyl)- 4-Methylbenzene

2020 ◽  
pp. 489-498
Author(s):  
Oleg S. Chudin ◽  
Victor V. Verpekin ◽  
Alexander A. Kondrasenko ◽  
Galina V. Burmakina ◽  
Dmitry V. Zimonin ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Carbonyl Group ◽  
Redox Properties ◽  
Substitution Reactions ◽  
Vinylidene Complexes ◽  
Ir And Nmr Spectroscopy ◽  
First Time

The binuclear μ-vinylidene complexes containing an isocyanide ligand (1-(isocyanomethylsulfonyl)-4-methylbenzene) Cp(CO)2RePt(μ-C=CHPh)(TosMIC)(L) [L = PPh3 (1), P(OPri)3 (2)] were synthesized for the first time. The approach afforded 1 and 2 based on the substitution reactions of a platinum bound carbonyl group in Cp(CO)2RePt(μ-C=CHPh)(CO)(L) [L = PPh3 (1a), P(OPri)3 (2a)] upon addition of 1-(isocyanomethylsulfonyl)-4-methylbenzene. The complexes 1 and 2 were characterized by IR and NMR spectroscopy. Their redox properties were studied

Coordination Behavior of tBu2PH towards [{Rh(μ-Cl)(coe)2}2] (coe = cis-cyclooctene): Crystal and Molecular Structure of [{Rh(μ-Cl)(tBu2PH)2}2]

2008 ◽  
Vol 63 (9) ◽  
pp. 1035-1039 ◽  
Author(s):  
Hans-Christian Böttcher ◽  
Peter Mayer
Keyword(s):  
Molecular Structure ◽  
Nmr Spectroscopy ◽  
Crystal And Molecular Structure ◽  
Molar Ratio ◽  
X Ray ◽  
X Ray Crystallography ◽  
Molar Ratios ◽  
H Nmr ◽  
Coordination Behavior ◽  
Independent Synthesis

The reaction of [{Rh(μ-Cl)(coe)2}2] (coe = cis-cyclooctene) with tBu2PH in different solvents in various molar ratios was investigated. Working with a molar ratio of Rh to P = 1 : 2 in heptane overnight afforded [{Rh(μ-Cl)(tBu2PH)2}2] (1) in nearly quantitative yield. Upon tuning the molar ratio (Rh/P) in the range from 1 : 2 to 1 : 0.5, 31P{1H} NMR spectroscopy indicated the formation of [(tBu2PH)2Rh(μ-Cl)2Rh(coe)2] (3) besides the complexes [{Rh(μ-Cl)(coe)(tBu2PH)}2] (cis, 2a; trans, 2b). The constitution of 3 was established by an independent synthesis mixing 1 with [{Rh(μ- Cl)(coe)2}2] or [{Rh(μ-Cl)(cod)}2] (cod = 1.4-cyclooctadiene), respectively, which also yielded [(tBu2PH)2Rh(μ-Cl)2Rh(cod)] (4). Single crystals of 1 have been analyzed by X-ray crystallography (monoclinic, Cc, Z = 8, a = 32.7375(3), b = 11.1294(1), c = 24.5134(3)Å ; β = 106.7228(4)◦; V = 8553.70(15) Å3; T = 200 (2) K).

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