TY - JOUR
T1 - Manganese carbonyl compounds reveal ultrafast metal-solvent interactions
AU - Aucott, Benjamin J.
AU - Duhme-Klair, Anne Kathrin
AU - Moulton, Benjamin E.
AU - Clark, Ian P.
AU - Sazanovich, Igor V.
AU - Towrie, Michael
AU - Hammarback, L. Anders
AU - Fairlamb, Ian J.S.
AU - Lynam, Jason M.
N1 - © 2019 American Chemical Society. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.
PY - 2019/6/10
Y1 - 2019/6/10
N2 - Herein, we exemplify that time-resolved multiple-probe spectroscopy (TR M PS) with infrared detection can be used to observe and quantify the dynamic processes occurring during the solvation of a catalytically competent manganese(I) carbonyl compound. TR M PS has been used to demonstrate that a manganese(I) 2-phenylpyridyl (ppy) complex, [Mn(ppy)(CO) 4 ], undergoes photochemically induced loss of a carbonyl ligand on a sub-picosecond time scale to give solvent (S) complexes of the type, fac-[Mn(ppy)(S)(CO) 3 ] (S = n-C 7 H 16 , CH 2 Cl 2 , NCMe, C 6 H 5 CH 3 , THF, 1,4-dioxane, n-Bu 2 O, and DMSO). An excited state, assigned as 3 [Mn(ppy)(CO) 4 ], with a lifetime, τ, of ca. 5 ps is also formed as a minor photoproduct. The vibrational modes of the carbonyl ligands in fac-[Mn(ppy)(S)(CO) 3 ] are diagnostic of the nature of the coordinated solvent and allow for the dynamics of solvation within the coordination of the metal to be observed. For example, in the case of THF, initial interactions with the metal occur through a C-H σ-interaction, assigned based on the similarity to the bands observed for the related heptane metal complex. Isomerization to the thermodynamically preferred O-binding mode was observed, τ ca. 18 ps, with similar behavior evident in 1,4-dioxane and n Bu 2 O. The lifetime for the isomerization shows a correlation with the number of C-H bonds in the solvent. In 1,4-dioxane, there is no evidence for the initial formation of an O-bound complex which indicates that the solvent binding is not stochastic in nature and is likely determined by the topology of the first solvation shell of the metal complex. The insight into these ultrafast metal-solvent interactions is enabled by the dominant photoprocess, CO dissociation, being rapid (<1 ps). Which, taken together with prompt vibrational cooling, enables the subtle interplay between metal and solvent during the solvation event to be characterized and quantified.
AB - Herein, we exemplify that time-resolved multiple-probe spectroscopy (TR M PS) with infrared detection can be used to observe and quantify the dynamic processes occurring during the solvation of a catalytically competent manganese(I) carbonyl compound. TR M PS has been used to demonstrate that a manganese(I) 2-phenylpyridyl (ppy) complex, [Mn(ppy)(CO) 4 ], undergoes photochemically induced loss of a carbonyl ligand on a sub-picosecond time scale to give solvent (S) complexes of the type, fac-[Mn(ppy)(S)(CO) 3 ] (S = n-C 7 H 16 , CH 2 Cl 2 , NCMe, C 6 H 5 CH 3 , THF, 1,4-dioxane, n-Bu 2 O, and DMSO). An excited state, assigned as 3 [Mn(ppy)(CO) 4 ], with a lifetime, τ, of ca. 5 ps is also formed as a minor photoproduct. The vibrational modes of the carbonyl ligands in fac-[Mn(ppy)(S)(CO) 3 ] are diagnostic of the nature of the coordinated solvent and allow for the dynamics of solvation within the coordination of the metal to be observed. For example, in the case of THF, initial interactions with the metal occur through a C-H σ-interaction, assigned based on the similarity to the bands observed for the related heptane metal complex. Isomerization to the thermodynamically preferred O-binding mode was observed, τ ca. 18 ps, with similar behavior evident in 1,4-dioxane and n Bu 2 O. The lifetime for the isomerization shows a correlation with the number of C-H bonds in the solvent. In 1,4-dioxane, there is no evidence for the initial formation of an O-bound complex which indicates that the solvent binding is not stochastic in nature and is likely determined by the topology of the first solvation shell of the metal complex. The insight into these ultrafast metal-solvent interactions is enabled by the dominant photoprocess, CO dissociation, being rapid (<1 ps). Which, taken together with prompt vibrational cooling, enables the subtle interplay between metal and solvent during the solvation event to be characterized and quantified.
UR - http://www.scopus.com/inward/record.url?scp=85073116977&partnerID=8YFLogxK
U2 - 10.1021/acs.organomet.9b00212
DO - 10.1021/acs.organomet.9b00212
M3 - Article
AN - SCOPUS:85066917291
SN - 0276-7333
VL - 38
SP - 2391
EP - 2401
JO - Organometallics
JF - Organometallics
IS - 11
ER -