Related Experiment Video

Updated: Feb 6, 2026

Identifying PD-1/PD-L1 Inhibitors with Surface Plasmon Resonance Technology

Identifying PD-1/PD-L1 Inhibitors with Surface Plasmon Resonance Technology

Published on: May 2, 2025

Kinetic and Mechanistic Aspects of Sulfur Recovery from Pd(2)I(2)(&mgr;-S)(&mgr;-dpm)(2) Using I(2) and Structures of Pd(II)

Terrance Y. H. Wong¹, Steven J. Rettig, Brian R. James

¹Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.

Inorganic Chemistry

|October 24, 2001

Abstract:

The Pd(2)X(2)(&mgr;-S)(dpm)(2) complexes (2) (X = I, Br) react with halogens to yield PdX(2)(dpm) (3) and elemental sulfur. Kinetic and mechanistic studies on the X = I system in CHCl(3) reveal that the reaction proceeds via addition of I(2) to give Pd(2)I(4)(dpm)(2) (4c), which then undergoes unimolecular decomposition to generate PdI(2)(dpm) (3c); the liberated sulfur concatenates to form elemental S(8). The addition reaction is in the stopped-flow time regime and is first-order in both 2c and I(2), with DeltaH() = 32 +/- 1 kJ mol(-)(1) and DeltaS() = -91 +/- 3 J K(-)(1) mol(-)(1). The slower decomposition reaction of 4c is first order in 4c, with DeltaH() = 80 +/-1 kJ mol(-)(1) and DeltaS() = -26 +/- 3 J K(-)(1) mol(-)(1). Byproduct PdX(2)(dpm(S)) (5) [dpm(S) = Ph(2)PCH(2)P(S)Ph(2)] also forms under some conditions via reaction of 3 with an S(n)() species (n < 8). Complexes 5 (X = Cl (a), Br (b), I (c)) were also synthesized directly, and the structure of the 5c species, as well as of [Pd(dpm(S))(2)]Cl(2), were determined by X-ray analyses that reveal the envelope configuration of the five-membered chelate ring.

More Related Videos

Preparation and Use of Samarium Diiodide SmI2 in Organic Synthesis: The Mechanistic Role of HMPA and NiII Salts in the Samarium Barbier Reaction

Preparation and Use of Samarium Diiodide SmI2 in Organic Synthesis: The Mechanistic Role of HMPA and NiII Salts in the Samarium Barbier Reaction

Published on: February 4, 2013

In Vivo 2-Photon Calcium Imaging in Layer 2/3 of Mice

In Vivo 2-Photon Calcium Imaging in Layer 2/3 of Mice

Published on: March 13, 2008

Related Concept Videos

SN2 Reaction: Kinetics

S_N2 Reaction: Kinetics

Kinetic Studies and Significance
In a chemical reaction, a relationship exists between the concentration of reactants and the rate at which the reaction proceeds. The study to measure this relationship is known as the kinetics of a chemical reaction. Kinetic studies are used to deduce the rate law of a chemical reaction, which provides information about the species involved during the transition state of the rate-determining step. Thus, kinetic studies help to derive the mechanism of a...

meta-Directing Deactivators: –NO2, –CN, –CHO, –&NoBreak;CO2R, –COR, –CO2H

meta-Directing Deactivators: –NO₂, –CN, –CHO, –⁠CO₂R, –COR, –CO₂H

All meta-directing substituents are deactivating groups. These substituents withdraw electrons from the aromatic ring, making the ring less reactive toward electrophilic substitution. For example, the nitration of nitrobenzene is 100,000 times slower than that of benzene because of the deactivating effect of the nitro group. The first step in an electrophilic aromatic substitution is the addition of an electrophile to form a resonance-stabilized carbocation. The energy diagrams for...

2° Amines to N-Nitrosamines: Reaction with NaNO2

2° Amines to N-Nitrosamines: Reaction with NaNO₂

Secondary amines react with nitrous acid to form N-nitrosamines, as depicted in Figure 1. Nitrous acid, a weak and unstable acid, is formed in situ from an aqueous solution of sodium nitrite and strong acids, such as hydrochloric acid or sulfuric acid, in cold conditions. In the presence of an acid, the nitrous acid gets protonated. The subsequent loss of water results in the formation of the electrophile known as nitrosonium ion.

SN2 Reaction: Mechanism

S_N2 Reaction: Mechanism

The kinetic studies of SN2 reactions suggest an essential feature of its mechanism: it is a single-step process without intermediates. Here, both the nucleophile and the substrate participate in the rate-determining step.
The presence of the more electronegative halogen in the substrate creates a polarized carbon-halide bond. The halide pulls the electron cloud generating an electrophilic center at the carbon atom. Thus, the carbon atom carries a partial positive charge while the halide has a...

SN2 Reaction: Transition State

S_N2 Reaction: Transition State

An SN2 reaction of an alkyl halide is a single-step process in which bond formation between the nucleophile and the substrate and bond breaking between the substrate and the halide occurs simultaneously through a transition state without forming an intermediate.
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...

SN2 Reaction: Stereochemistry

S_N2 Reaction: Stereochemistry

In an SN2 reaction, the nucleophilic attack on the substrate and departure of the leaving group occurs simultaneously through a transition state. As the nucleophile approaches the substrate from the back-side, the configuration of the substrate carbon changes from tetrahedral to trigonal bipyramidal and then back to tetrahedral, leading to an inversion in the configuration of the product.
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not...

Articles linked to this work by shared authors, journal, and citation graph.

Synthesis, Structure, and Reactivity of [RuCl(PP)L]PF(6) (PP = (PPh(3))(2), Ph(2)P(CH(2))(4)PPh(2); L = P(py)(3), PPh(py)(2), py = 2-pyridyl). The "Missing" P,N,N'-Coordination Mode for 2-Pyridylphosphines.

Inorganic chemistry·2001

Synthesis and Structure of a Zirconium Dinitrogen Complex with a Side-On Bridging N(2) Unit.

Inorganic chemistry·2001

Pyramidal Inversion at Phosphorus Facilitated by the Presence of Proximate Lewis Acids. Coordination Chemistry of Group 13 Elements with the Macrocyclic Bis(amidophosphine) Ligand [P(2)N(2)] ([P(2)N(2)] = [PhP(CH(2)SiMe(2)NSiMe(2)CH(2))(2)PPh]).

Inorganic chemistry·2001

Synthesis and Structure of [{Mo(CO)(4)}(2)(cis-&mgr;-F(2)SbF(4))(3)](x)()[Sb(2)F(11)](x)(): An Ionic Coordination Polymer.

Inorganic chemistry·2001

Stoichiometric O(2) Oxidation of Bis(Thioether)(Octaethylporphyrinato)ruthenium(II) Complexes to the Corresponding Sulfoxide Species in Acidic Media. Structural Confirmation of S-Bonded Sulfoxides.

Inorganic chemistry·2001

Synthesis and Structure of a New Lithium Amide Ligand Precursor: A Tridentate Nitrogen-Based Donor Set of the Formula N(SiMe(2)CH(2)NMe(2))(2). Synthesis and Structure of the Group 4 Amides MCl(3)[N(SiMe(2)CH(2)NMe(2))(2)] (M = Ti, Zr, Hf).

Inorganic chemistry·1997

See all related articles