Effects of calcium on the kinetics of a model disjunctive ligand exchange reaction: implications for dynamic trace metal ion speciation

2019 ◽  
Vol 21 (1) ◽  
pp. 89-103
Author(s):  
Laura T. Rea ◽  
Yi Xu ◽  
Nathan E. Boland
Keyword(s):  
Trace Metal ◽  
Exchange Reaction ◽  
Ligand Exchange ◽  
Metal Ion ◽  
Multidentate Ligands ◽  
Kinetic Behavior ◽  
Exchange Reactions ◽  
Ligand Exchange Reaction ◽  
Calcium Affinity ◽  
Kinetics Of

Differences in the calcium affinity of exchanging multidentate ligands affect the kinetic behavior of disjunctive ligand exchange reactions.

An all-in-one approach for synthesis and functionalization of nano colloidal gold with acetylacetone

2021 ◽  
Author(s):  
Li Zhang ◽  
Hongcen Zheng ◽  
Yonghai Gan ◽  
Bingdang Wu ◽  
Zhihao Chen ◽  
...  
Keyword(s):  
Exchange Reaction ◽  
Ligand Exchange ◽  
Fold Increase ◽  
Charge Transfer Complexes ◽  
Photochemical Property ◽  
Exchange Reactions ◽  
Ligand Exchange Reaction ◽  
Enhanced Photoluminescence ◽  
Good Imaging ◽  
Imaging Probes

Abstract Controllable synthesis, proper dispersion, and feasible functionalization are crucial requirements for the application of nanomaterials in many scenarios. Here, we report an all-in-one approach for the synthesis and functionalization of gold nanoparticles (AuNPs) with the simplest β-diketone, acetylacetone (AcAc). With this approach, the particle size of the resultant AuNPs was tunable by simply adjusting the light intensity or AcAc dosage. Moreover, owing to the capping role of AcAc, the resultant AuNPs could be stably dispersed in water for a year without obvious change in morphology and photochemical property. Formation of ligand to metal charge transfer complexes was found to play an important role in the redox conversion of Au with AcAc. Meanwhile, the moderate complexation ability enables the surface AcAc on the AuNPs to undergo ligand exchange reactions. With the aid of Ag+, the AuNPs underwent ligand exchange reaction with glutathione and exhibited enhanced photoluminescence (PL) with a maximum of 22-fold increase in PL intensity. The PL response was linear to the concentration of glutathione in the range of 0~500 μM. Such a ligand exchange reaction makes the obtained AuNPs being good imaging probes. To the best of our knowledge, this is the first work on illustrating the roles of AcAc as a multifunctional ligand in fabrication of NPs, which sheds new light on the surface modulation in synthesis of nanomaterials.

Ligandenaustauschreaktionen zwischen Halogenboranen und Alkylsilanen/Ligand Exchange Reactions between Haloboranes and Alkylsilanes

1990 ◽  
Vol 45 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Wolfgang Einholz ◽  
Walter Gollinger ◽  
Wolfgang Haubold
Keyword(s):  
Exchange Reaction ◽  
Ligand Exchange ◽  
Exchange Reactions ◽  
Ligand Exchange Reaction

Abstract In a ligand exchange reaction between BHal3 (Hal = Cl, Br) and the tetraalkylsilanes Et4Si, (Me3Si)2CH2 or Ph2CHSiMe3 the alkylhaloboranes EtBBr2 or MeBHal2 and the alkylhalosilanes Et3SiBr, HalMe2Si-CH2-SiMe3, (HalMe2Si)2CH2, and Ph2CHSiMe2Br, respectively, are formed. Similarly, the methyloligosilanes (Me3Si)2 (1) and (Me3Si)2SiMe2 (2) react with BHal3 (Hal = Cl, Br, I) via methyl-halogen-transfer to give HalMe2Si-SiMe3 (Hal = Cl, Br, I), (HalMe2Si)2 (Hal = Br, I), HalMe2Si - SiMe2-SiMe3, (Me3Si)2SiMeHal, HalMe2Si - SiMeHal -SiMe3, (HalMe2Si)SiMe2 (Hal = Cl, Br) or (BrMe2Si)2SiMeBr besides MeBHal2 (Hal = Cl, Br, I) and Me2BI, respectively.

Ligand exchange reactions between ferrocene and 9,10-dimethylanthracene

1978 ◽  
Vol 56 (13) ◽  
pp. 1782-1787 ◽  
Author(s):  
Ronald G. Sutherland ◽  
W. Jack Pannekoek ◽  
Choi Chuck Lee
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Exchange Reaction ◽  
Aromatic Hydrocarbons ◽  
Ligand Exchange ◽  
Ring System ◽  
Exchange Reactions ◽  
Ligand Exchange Reaction ◽  
Polycyclic Aromatic

The reaction of 9,10-dimethylanthracene (8) with ferrocene (FcH) in the presence of AlCl3–Al in decalin gave the stereospecifically hydrogenated product, η6-cis-(endo-9,10-dihydro)-9,10-dimethylanthracene-η5-cyclopentadienyliron cation (10a), the hydrogenation at C-9,10 being cis and endo or on the same side as the cyclopentadienyliron (CpFe) moiety. When cis-9,10-dihydro-9,10-dimethylanthracene, generated from 10a by photolysis or pyrolytic sublimation, was used as the arene in the ligand exchange reaction, complexing with the CpFe group could occur from either side of the ring system, giving rise to a mixture of 10a and the η6-cis-(exo-9,10-dihydro)-9,10-dimethylanthracene-η5-cyclopentadienyliron cation (10b). The η6-cis-9,10-dihydro-9,10-dimethylanthracene-trans-bis-η5-cyclopentadienyliron dication, with the two CpFe groups trans, was also prepared either from a stepwise ligand exchange using 10a or directly from reaction of 8 using an excess of FcH. A mechanism is proposed for the hydrogenation that has been found to accompany ligand exchange reactions between polycyclic arenes and FcH and possible applications are pointed out for the synthesis of partially hydrogenated polycyclic aromatic hydrocarbons.

Ligand Exchange and Redox Reactions of Chromium(V): Isolation of the Chromium(V) Oxalato Complexes From the Ligand Exchange Reaction of Bis[2-ethyl-2-hydroxybutanoato(2-)]oxochromate(V) With Oxalate in 50% Aqueous Acetic Acid

1990 ◽  
Vol 43 (2) ◽  
pp. 263 ◽  
Author(s):  
R Bramley ◽  
RP Farrell ◽  
JY Ji ◽  
PA Lay
Keyword(s):  
Oxalic Acid ◽  
Exchange Reaction ◽  
Ligand Exchange ◽  
Electrochemical Techniques ◽  
Equilibrium Mixture ◽  
Aqueous Acetic Acid ◽  
Exchange Reactions ◽  
Ligand Exchange Reaction ◽  
General Utility ◽  
The Difference

The moderately stable chromium(v) complex, trans-bis[2-ethyl-2-hydroxybutanoato(2-)] oxo -chromate(v), [Cr( ehba )2O]- (1), has been assessed for its suitability as a synthetic intermediate for the preparation of other chromium(v) complexes. This complex undergoes a ligand exchange reaction with excess oxalic acid to form an equilibrium mixture of chromium(v) complexes which have been assigned the structures [Cr( ehba )2O]-, [Cr( ehba )(ox)O]- (2), [Cr(ox)2O]- (3) and cis -[Cr(ox)2(OH2)O]- (4). The products of the ligand exchange reaction were characterized by a combination of u.v ./visible spectroscopy, e.p.r . spectroscopy and electrochemistry. The equilibrium mixture of chromium(v) complexes decays to form chromium(III) products by a redox reaction which is much slower than the initial ligand exchange reaction. The difference in the rates of ligand exchange and subsequent reduction allows the extraction of the chromium(v) ligand exchange products into dichloromethane. n.m.r. spectroscopy and electrochemical techniques were used to identify these products. Under appropriate conditions (high oxalic acid concentrations) the major species extracted are the bis [ oxalato (2-)] oxochromate (v) complexes which have been isolated as oily solids in relatively pure form (≥90% pure) for the first time. n.m.r. spectroscopic evidence indicates that the isolated solid was a mixture of (3) and (4) which explains the difficulty encountered in crystallizing the solid. These ligand exchange reactions may be of general utility in the synthesis of chromium(v) complexes.

Kinetics of trace metal complexation: ligand-exchange reactions

1990 ◽  
Vol 24 (2) ◽  
pp. 242-252 ◽  
Author(s):  
Janet G. Hering ◽  
Francois M. M. Morel
Keyword(s):  
Trace Metal ◽  
Ligand Exchange ◽  
Metal Complexation ◽  
Exchange Reactions ◽  
Kinetics Of
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