Synthetic, Structural, NMR, and Computational Study of a Geminally Bis(peri-substituted) Tridentate Phosphine and Its Chalcogenides and Transition-Metal Complexes

2013 ◽  
Vol 52 (8) ◽  
pp. 4346-4359 ◽  
Author(s):  
Matthew J. Ray ◽  
Rebecca A. M. Randall ◽  
Kasun S. Athukorala Arachchige ◽  
Alexandra M. Z. Slawin ◽  
Michael Bühl ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Computational Study

scholarly journals Should External Heavy-Atom Effects be Expected in Transition Metal Complexes?

2018 ◽  
Author(s):  
Justin Lomont ◽  
Son Nguyen ◽  
Charles Harris
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Spin State ◽  
Computational Study ◽  
Heavy Atom ◽  
Minimum Energy ◽  
Free Energy Barrier ◽  
Heavy Atom Effect ◽  
Atom Effect

Spin state changes frequently play a key role in the reactivity of transition metal complexes. The rates of spin-forbidden reactions are mediated both by the free energy barrier connecting reactants and products, as well as the strength of spin-orbit coupling (SOC) between the relevant electronic states. Since the 1950’s, there have been numerous demonstrations of external heavy-atom effects on organic molecules, in which a heavy atom, not chemically bonded to the molecule undergoing a change in spin state, perturbs the strength of SOC via an intermolecular effect. However, the potential role of external heavy atom effects on the rates of reactions involving transition metal complexes remains almost entirely unexplored. We report a computational investigation into the changes in SOC that occur along a bimolecular reaction coordinate when an incoming atom coordinates to the prototypical triplet reaction intermediate Fe(CO)4. The calculated changes in SOC are compared for molecules containing atoms ranging in atomic number from Z = 8 to Z = 53 approaching the Fe center (ZFe =26). No evidence for an external heavy atom effect was found, and the changes in SOC with the approach of each incoming group were similar in magnitude. In fact, when taking into account the different minimum energy crossing point geometries for the different incoming groups, the opposite of an external heavy atom effect trend is predicted for this reaction. The results of this computational study suggest that external heavy atom effects are unlikely to have a significant effect on the rates of spin-forbidden reactions for transition metal complexes. <br>

N-Heterocyclic Phosphenium, Arsenium, and Stibenium Ions as Ligands in Transition Metal Complexes: A Comparative Experimental and Computational Study

2005 ◽  
Vol 631 (8) ◽  
pp. 1403-1412 ◽  
Author(s):  
Sebastian Burck ◽  
Jörg Daniels ◽  
Timo Gans-Eichler ◽  
Dietrich Gudat ◽  
Kalle Nättinen ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Computational Study

A Computational Study on Fluxional Behavior of Group 6 and 7 Transition-metal Complexes of Borane–Lewis Base Adducts

2006 ◽  
Vol 35 (6) ◽  
pp. 568-569 ◽  
Author(s):  
Yasuro Kawano ◽  
Taeko Kakizawa ◽  
Kazunori Yamaguchi ◽  
Mamoru Shimoi
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Computational Study ◽  
Lewis Base ◽  
Group 6

scholarly journals Should External Heavy-Atom Effects be Expected in Transition Metal Complexes?

2018 ◽  
Author(s):  
Justin Lomont ◽  
Son Nguyen ◽  
Charles Harris
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Spin State ◽  
Computational Study ◽  
Heavy Atom ◽  
Minimum Energy ◽  
Free Energy Barrier ◽  
Heavy Atom Effect ◽  
Atom Effect

Spin state changes frequently play a key role in the reactivity of transition metal complexes. The rates of spin-forbidden reactions are mediated both by the free energy barrier connecting reactants and products, as well as the strength of spin-orbit coupling (SOC) between the relevant electronic states. Since the 1950’s, there have been numerous demonstrations of external heavy-atom effects on organic molecules, in which a heavy atom, not chemically bonded to the molecule undergoing a change in spin state, perturbs the strength of SOC via an intermolecular effect. However, the potential role of external heavy atom effects on the rates of reactions involving transition metal complexes remains almost entirely unexplored. We report a computational investigation into the changes in SOC that occur along a bimolecular reaction coordinate when an incoming atom coordinates to the prototypical triplet reaction intermediate Fe(CO)4. The calculated changes in SOC are compared for molecules containing atoms ranging in atomic number from Z = 8 to Z = 53 approaching the Fe center (ZFe =26). No evidence for an external heavy atom effect was found, and the changes in SOC with the approach of each incoming group were similar in magnitude. In fact, when taking into account the different minimum energy crossing point geometries for the different incoming groups, the opposite of an external heavy atom effect trend is predicted for this reaction. The results of this computational study suggest that external heavy atom effects are unlikely to have a significant effect on the rates of spin-forbidden reactions for transition metal complexes. <br>

Mechanochemical changes on cyclometalated Ir(iii) acyclic carbene complexes – design and tuning of luminescent mechanochromic transition metal complexes

2020 ◽  
Vol 7 (3) ◽  
pp. 786-794 ◽  
Author(s):  
Jingqi Han ◽  
Kin-Man Tang ◽  
Shun-Cheung Cheng ◽  
Chi-On Ng ◽  
Yuen-Kiu Chun ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Carbene Complexes ◽  
New Class

A new class of luminescent cyclometalated Ir(iii) complexes with readily tunable mechanochromic properties derived from the mechanically induced trans-to-cis isomerization have been developed.

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