Heterobimetallic catechol-phosphine complexes with palladium and a group-13 element: structural flexibility and dynamics

G. Bauer; M. Nieger; D. Gudat

doi:10.1039/c4dt00785a

Heterobimetallic catechol-phosphine complexes with palladium and a group-13 element: structural flexibility and dynamics

Dalton Transactions ◽

10.1039/c4dt00785a ◽

2014 ◽

Vol 43 (23) ◽

pp. 8911-8920 ◽

Cited By ~ 5

Author(s):

G. Bauer ◽

M. Nieger ◽

D. Gudat

Keyword(s):

Relative Stability ◽

Structural Flexibility ◽

Nmr Studies ◽

Proton Mobility ◽

Group 13 ◽

H Nmr ◽

Phosphine Complexes ◽

Insight Into

Condensation of a catechol phosphine Pd complex [Pd(catphosH)2] with group-13 element acetylacetonates yields complexes [M(L)n(catphos)2Pd] or [M{(catphos)2Pd}2]H (M = Al, Ga, In) whose relative stability is controlled by the size of the group-13 element. 1H NMR studies give insight into the proton mobility in a Pd2In complex.

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19F NMR studies on γ-butyrobetaine hydroxylase provide mechanistic insights and suggest a dual inhibition mode

Chemical Communications ◽

10.1039/c9cc06466d ◽

2019 ◽

Vol 55 (98) ◽

pp. 14717-14720

Author(s):

Robert K. Leśniak ◽

Anna M. Rydzik ◽

Jos J. A. G. Kamps ◽

Amjad Kahn ◽

Timothy D. W. Claridge ◽

...

Keyword(s):

Ligand Binding ◽

19F Nmr ◽

Nmr Studies ◽

H Nmr ◽

Mechanistic Insight ◽

Dual Inhibition ◽

Insight Into

19F and 1H NMR studies on fluorine labelled γ-butyrobetaine hydroxylase provide mechanistic insight into substrate and ligand binding, suggesting cooperativity between two monomers.

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Neuartige basische Liganden für die homogenkatalytische Methanolcarbonylierung, XXXI Kationische Bis(Ether-Phosphan)metall-Komplexe der Nickeltriade mit fluktuierendem Verhalten / Novel Basic Ligands for the Homogeneous Catalytic Methanol Carbonylation, XXXI Cationic Bis(Ether-Phosphine)Metal Complexes of the Nickel Triad with Fluxional Behavior

Zeitschrift für Naturforschung B ◽

10.1515/znb-1991-0403 ◽

1991 ◽

Vol 46 (4) ◽

pp. 432-439 ◽

Cited By ~ 8

Author(s):

Ekkehard Lindner ◽

Johannes Dettinger

Keyword(s):

Metal Complexes ◽

Nmr Spectra ◽

Palladium Complexes ◽

Phosphine Ligands ◽

Temperature Dependent ◽

H Nmr ◽

Phosphine Complexes ◽

Metal Phosphides ◽

Ether Oxygen ◽

Insight Into

The (ether-phosphine) ligands R2PCH2C5H9O (1a-c) [R = Ph (a), Cy (= cyclo-C6H11) (b), n-C3H7 (c); C5H9O = tetrahydropyranyl] are obtained from the corresponding alkali metal phosphides MPR2 (M = Li, Na) and 2-chloromethyltetrahydropyran in ether. Reaction of 1 a-c with either Cl2M(COD) (COD = 1,5-cyclooctadiene) or [Ni(OH2)6]Cl2 in a2:1 ratio leads to the bis(ether-phosphine)metal complexes Cl2M(R2P∾O)2 trans-2b,c, trans-3b, cis-2a,b, cis-3a, and 4a [M = Pd (2), Pt (3), Ni (4)], in which the ligands 1a-c are η1-P-coordinated. In 2—4 Cl- is abstracted by AgClO4 to give the cationic trans-bis(ether-phosphine) complexes [ClM(R2P ∾ O)(R2P~O)][ClO4] (5a, 6a-c, 7a) [M = Ni (5), Pd (6), Pt (7); P∾O = η1-P-coordinated; P~O = η2-O,P-coordinated]. In contrast to 7a, the nickel and palladium complexes 5a and 6a-c show fluxional behavior as demonstrated by temperature dependent 31P{1H} NMR spectra. The coalescence temperatures and estimated free energie enthalpies ΔG≉ of 5a and 6a-c are compared with the corresponding data of the complexes [ClPd(Ph2P ∾ O)(Ph2~O)][ClO4] (8a-10a) [O,P ligand = Ph2PCH2C4H7O (8a), Ph2PCH2C4H7O2 (9a), Ph2PCH2CH2OCH3 (10a)] and give an insight into the relative basicity of the ether oxygen atoms.

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1H NMR Conformational Studies in Water of Angiotensin II Analogues Modified at the N- and C-Termini: Interactions of the Aromatic Side Chains and Folding of the N-Terminal Domain

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19942523 ◽

1994 ◽

Vol 59 (11) ◽

pp. 2523-2532 ◽

Cited By ~ 4

Author(s):

John Hondrelis ◽

John Matsoukas ◽

George Agelis ◽

Paul Cordopatis ◽

Ning Zhou ◽

...

Keyword(s):

Shielding Effect ◽

Resonance Spectroscopy ◽

Nmr Studies ◽

Previous Suggestion ◽

Aminoisobutyric Acid ◽

H Nmr ◽

Neutral Ph ◽

Angiotensin Ii Analogues ◽

Proton Resonances ◽

Cosy Nmr

The conformation of [Sar1]angiotensin II in water at neutral pH has been examined by proton magnetic resonance spectroscopy at 400 MHz and in particular by comparing its 1H NMR spectral data with those of analogues modified at positions 1,4 and 6, namely [Sar1,Cha8]ANGII, [Des Asp1,Cha8]ANGII, [Aib1,Tyr(Me)4]ANGII, [Aib1,Tyr(Me)4,Ile8]ANGII, [N-MeAib1,Tyr(Me)4]ANGII, [N-MeAib1,Tyr(Me)4,Ile8]ANGII, ANGIII and [Sar1,Ile8]ANGII. Assignment of all proton resonances in these analogues was made possible by 2D COSY NMR experiments. The H-2 and H-4 protons for the histidine ring in [Sar1]ANGII, ANGII and ANGIII were shielded compared with the same protons in [Sar1,Ile8]ANGII, [Sar1,Cha8]ANGII and [Des Asp1,Cha8]ANGII; this shielding effect was not disturbed upon methylation of the tyrosine hydroxyl and/or replacement of residue 1 (sarcosine or aspartic acid) with aminoisobutyric acid (Aib) or N-methyl aminoisobutyric acid (N-MeAib). These data are consistent with our previous suggestion based on NMR studies in neutral DMSO that a characteristic folded conformation for ANGII previously observed in non-polar solvents can also be detected in water at neutral pH, but to a lesser degree.

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ChemInform Abstract: PYRIMIDINE DERIVATIVES PART 48, PMR-STUDIES ON SIGMA-ADDUCTS OF HETEROCYCLIC SYSTEMS WITH NUCLEOPHILES PART 5, (1)H NMR STUDIES OF SIGMA-ADDUCTS OF PTERIDINE AND SOME OF ITS DERIVATIVES IN LIQUID AMMONIA

Chemischer Informationsdienst ◽

10.1002/chin.197525288 ◽

1975 ◽

Vol 6 (25) ◽

pp. no-no

Author(s):

A. NAGEL ◽

H. C. VAN DER PLAS ◽

A. VAN VELDHUIZEN

Keyword(s):

Liquid Ammonia ◽

Pyrimidine Derivatives ◽

Nmr Studies ◽

H Nmr

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Field- and Temperature-Dependent 13C NMR Studies of the EDTA–Zn2+ Complex: Insight into Structure and Dynamics via Relaxation Measurements

The Journal of Physical Chemistry B ◽

10.1021/jp507674a ◽

2014 ◽

Vol 118 (45) ◽

pp. 12960-12964 ◽

Cited By ~ 2

Author(s):

Sriramya Garapati ◽

Colin S. Burns ◽

A. A. Rodriguez

Keyword(s):

13C Nmr ◽

Temperature Dependent ◽

Nmr Studies ◽

Structure And Dynamics ◽

Relaxation Measurements ◽

Insight Into

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High field 1H NMR Studies of Sol-Gel Kinetics

MRS Proceedings ◽

10.1557/proc-73-157 ◽

1986 ◽

Vol 73 ◽

Cited By ~ 7

Author(s):

Bruce D. Kay ◽

Roger A. Assink

Keyword(s):

Equilibrium Distribution ◽

Sol Gel ◽

Nmr Studies ◽

H Nmr ◽

Rate Limiting Step ◽

Rate Of Hydrolysis ◽

Acid Catalyzed ◽

Product Species ◽

Rate Limiting ◽

Kinetics Of

ABSTRACTHigh resolution 1H NMR spectroscopy at high magnetic fields is employed to study the reaction kinetics of the Si(OCH3)4:CH3OH:H2O sol-gel system. Both the overall extent of reaction as a function of time and the equilibrium distribution of species are measured. In acid catalyzed solution, condensation is the rate limiting step while in base catalyzed solution, hydrolysis becomes rate limiting. A kinetic model in which the rate of hydrolysis is assumed to be independent of the adjacent functional groups is presented. This model correctly predicts the distribution of product species during the initial stages of the sol-gel reaction.

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Equilibrium thermodynamic studies for the formation of 1:1 complexes of CO and ethene with a rhodium(II) porphyrin metallo-radical

Canadian Journal of Chemistry ◽

10.1139/v01-052 ◽

2001 ◽

Vol 79 (5-6) ◽

pp. 854-856 ◽

Cited By ~ 9

Author(s):

Leah Basickes ◽

Andrew G Bunn ◽

Bradford B Wayland

Keyword(s):

Carbon Monoxide ◽

Complex Formation ◽

Equilibrium Thermodynamic ◽

Nmr Studies ◽

Thermodynamic Studies ◽

H Nmr ◽

Porphyrin Ligand ◽

The One ◽

Paramagnetic Shifts

Tetra(2,4,6 triisopropropyl phenyl)porphyrinatorhodium(II) ((TTiPP)RhII·1) is a persistent metal-centered radical with the odd electron in the rhodium(II) dz2 orbital. (TTiPP)RhII· forms 1:1 complexes with CO and CH2CH2 where the porphyrin ligand steric properties inhibit further reactions of the one-electron activated substrates. 1H NMR paramagnetic shifts at a series of temperatures are used in evaluating the thermodynamics for CO complex formation with 1 to form [(TTiPP)RhII(CO)]·2 (ΔH° = -5.5 ± 0.5 kcal mol-1; ΔS° = -9 ± 1 cal K-1 mol-1). Related 1H NMR studies show that the bonding of 1 with ethene is less favorable than CO.Key words: rhodium porphyrin, carbon monoxide, ethene, thermodynamics, complex formation, metal-centered radical.

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The synthesis of 11R- and 11S-HETE and of 11-R,S-HPETE methyl esters

Canadian Journal of Chemistry ◽

10.1139/v83-132 ◽

1983 ◽

Vol 61 (4) ◽

pp. 712-717 ◽

Cited By ~ 13

Author(s):

George Just ◽

Corinne Luthe ◽

Minh Tan Phan Viet

Keyword(s):

Methyl Esters ◽

Nmr Studies ◽

H Nmr ◽

Conformational Properties

Methyl 11R- and 11S-hydroxyeicosa-5Z,8Z,12E,14Z-tetraenoate (17R, 17S) (11-HETE) and the corresponding 11-hydroperoxide 19 (11-HPETE) have been prepared from readily available starting materials. The yields were approximately 25% for 11R,S-HETE, and 5% each for 11R- and 11S-HETE.Extensive 400 MHz 1H nmr studies of 17 (nOe difference, 2D J-resolved) were undertaken to confirm the structure. Some conformational properties are discussed.

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