Probing Organometallic Reactions by Time-Resolved Infrared Spectroscopy in Solution and in the Solid State Using Quantum Cascade Lasers

Abstract

The photochemistry and photophysics of metal carbonyl compounds (W(CO)₆,Cp*Rh(CO)₂ (Cp* = η⁵-C₅Me₅), and fac-[Re(CO)₃(4,4'-bpy)₂Br] [bpy = bipyridine]) have been examined on the nanosecond timescale using a time-resolved infrared spectrometer with an external cavity quantum cascade laser (QCL) as the infrared source. We show the photochemistry of W(CO)₆ in alkane solution is easily monitored, and very sensitive measurements are possible with this approach, meaning it can monitor small transients with absorbance changes less than 10-⁶ DOD. The C–H activation of Cp*Rh(CO)(C₆H₁₂)to form Cp*Rh(CO)(C₆H₁₁)H occurs within the first few tens of nanoseconds following photolysis, and we demonstrate that kinetics obtained following deconvolution are in excellent agreement with those measured using an ultrafast laser-based spectrometer. We also show that the high flux and tunability of QCLs makes them suited for solid-state and time-resolved measurements.

Keywords

Quantum cascade laser QCL Photochemistry Time-resolved Infrared TRIR

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References

George

M.W.

Poliakoff

Turner

J.J.

. “Nanosecond Time-Resolved Infrared Spectroscopy: A Comparative View of Spectrometers and Their Applications in Organometallic Chemistry”. Analyst. 1994. 119(4): 551–560.

Schoonover

J.R.

Strouse

G.F.

. “Time-Resolved Vibrational Spectroscopy of Electronically Excited Inorganic Complexes in Solution”. Chem. Rev. 1998. 98(4): 1335–1356.

Butler

J.M.

George

M.W.

Schoonover

J.R.

Dattelbaum

D.M.

Meyer

T.J.

. “Application of Transient Infrared and Near Infrared Spectroscopy to Transition Metal Complex Excited States and Intermediates”. Coord. Chem. Rev. 2007. 251(3-4): 492–514.

Smith

J.A.

George

M.W.

Kelly

J.M.

. “Transient Spectroscopy of Dipyridophenazine Metal Complexes Which Undergo Photo-Induced Electron Transfer with DNA”. Coord. Chem. Rev. 2011. 255(21-22): 2666–2675.

Garrett-Roe

Hamm

. “What Can We Learn from Three-Dimensional Infrared Spectroscopy?” Acc. Chem. Res. 2009. 42(9): 1412–1422.

Ganim

Chung

H.S.

Smith

A.W.

DeFlores

L.P.

Jones

K.C.

Tokmakoff

. “Amide I Two-Dimensional Infrared Spectroscopy of Proteins”. Acc. Chem. Res. 2008. 41(3): 432–441.

Zheng

Kwak

Fayer

M.D.

. “Ultrafast 2D IR Vibrational Echo Spectroscopy”. Acc. Chem. Res. 2007. 40: 75–83.

Toscano

J.P.

. “Structure and Reactivity of Organic Intermediates as Revealed by Time-Resolved Infrared Spectroscopy”. In: Neckers

D.C.

Von Büneau

, editors. Advanced Photochemistry. Hoboken, NJ: John Wiley and Sons, 2001. Vol. 26. Pp. 41–91.

Tanner

K.N.

King

R.L.

. “Infra-red Spectra of Free Radicals”. Nature. 1958. 181: 963–965.

10.

Siebert

Mäntele

Kreutz

. “Flash-Induced Kinetic Infrared Spectroscopy Applied to Biochemical Systems”. Biophys. Struct. Mech. 1980. 6(2): 139–146.

11.

Smith

G.D.

Palmer

R.A.

. “Fast Time-Resolved Mid-Infrared Spectroscopy Using an Interferometer”. In: Chalmers

J.M.

Griffiths

P.R.

, editors. Handbook of Vibrational Spectroscopy. Chichester, UK: John Wiley and Sons, 2006. Vol. 1. Pp. 625–640.

12.

Fayer

. Ultrafast Infrared and Raman Spectroscopy. New York, NY: Marcel Dekker, 2001. Vol. 2.

13.

Remorino

Hochstrasser

R.M.

. “Three-Dimensional Structures by Two-Dimensional Vibrational Spectroscopy”. Acc. Chem. Res. 2012. 45(11): 1896–1905.

14.

Nibbering

E.T.J.

Elsaesser

. “Ultrafast Vibrational Dynamics of Hydrogen Bonds in the Condensed Phase”. Chem. Rev. 2004. 104(4): 1887–1914.

15.

Greetham

G.M.

Sole

Clark

I.P.

Parker

A.W.

Pollard

M.R.

Towrie

. “Time-Resolved Multiple Probe Spectroscopy”. Rev. Sci. Instrum. 2012. 83: 103107–5.

16.

Greetham

G.M.

Burgos

Cao

Clark

I.P.

Codd

P.S.

Farrow

R.C.

George

M.W.

Kogimtzis

Matousek

Parker

A.W.

Pollard

M.R.

Robinson

D.A.

Xin

Z.-J.

Towrie

. “ULTRA: A Unique Instrument for Time-Resolved Spectroscopy”. Appl. Spectrosc. 2010. 64(12): 1311–1319.

17.

Hancock

Horrocks

S.J.

Ritchie

G.A.D.

Helden

J.H. v.

Walker

R.J.

. “Time-Resolved Detection of the CF3 Photofragment Using Chirped QCL Radiation”. J. Phys. Chem. A. 2008. 112(40): 9751–9757.

18.

Hancock

Ritchie

van Helden

J.-P.

Walker

Weidmann

. “Applications of Midinfrared Quantum Cascade Lasers to Spectroscopy”. Opt. Eng. 2010. 49(11): 111121–7.

19.

Welzel

Gatilova

Röpcke

Rousseau

. “Time-Resolved Study of a Pulsed dc Discharge Using Quantum Cascade Laser Absorption Spectroscopy: NO and Gas Temperature Kinetics”. Plasma Sources Sci. Technol. 2007. 16(4): 822–831.

20.

Grills

D.C.

Farrington

J.A.

Layne

B.H.

Lymar

S.V.

Mello

B.A.

Preses

J.M.

Wishart

J.F.

. “Mechanism of the Formation of a Mn-Based CO₂ Reduction Catalyst Revealed by Pulse Radiolysis with Time-Resolved Infrared Detection”. J. Am. Chem. Soc. 2014. 136(15): 5563–5566.

21.

Lewandowska-Andralojc

Grills

D.C.

Zhang

Bullock

R.M.

Miyazawa

Kawanishi

Fujita

. “Kinetic and Mechanistic Studies of Carbon-to-Metal Hydrogen Atom Transfer Involving Os-Centered Radicals: Evidence for Tunneling”. J. Am. Chem. Soc. 2014. 136(9): 3572–3578.

22.

Marinov

Lopatik

Guaitella

Hübner

Ionikh

Röpcke

Rousseau

. “Surface Vibrational Relaxation of N₂ Studied by CO₂ Titration with Time-Resolved Quantum Cascade Laser Absorption Spectroscopy”. J. Phys. D: Appl. Phys. 2012. 45: 175201.

23.

Welzel

Stepanov

Meichsner

Röpcke

. “Time Resolved Studies on Pulsed Fluorocarbon Plasmas Using Chirped Quantum Cascade Lasers”. J. Phys. D: Appl. Phys. 2010. 43(12): 124014.

24.

Giordano

P.J.

Wrighton

M.S.

. “The Nature of the Lowest Excited State in fac-Tricarbonylhalobis(4-Phenylpyridine)Rhenium(I) and fac-Tricarbonylhalobis(4,4′-Bipyridine)Rhenium(I): Emissive Organometallic Complexes in Fluid Solution”. J. Am. Chem. Soc. 1979. 101(11): 2888–2897.

25.

Hermann

Grevels

F.W.

Henne

Schaffner

. “Flash Photolysis with Infrared Detection: The Photochemistry and Secondary Thermal Reactions of M(CO)₆ [M = Cr, Mo, and W]”. J. Phys. Chem. 1982. 86(26): 5151–5154.

26.

Breheny

C.J.

Kelly

J.M.

Long

O'Keeffe

Pryce

M.T.

Russell

Walsh

M.M.

. “Photochemistry of (Arene)Mo(CO)₃ and the Role of Alkane Solvents in Modifying the Reactions of Coordinatively Unsaturated Metal Carbonyl Fragments”. Organometallics. 1998. 17(17): 3690–3695.

27.

Cowan

A.J.

Portius

Kawanami

H.K.

Jina

O.S.

Grills

D.C.

Sun

X.Z.

McMaster

George

M.W.

. “Time-Resolved Infrared Study on the Formation and Reactivity of Organometallic Methane and Ethane Complexes in Room Temperature Solution”. Proc. Natl. Acad. Sci. U.S.A. 2007. 104(17): 6933–6938.

28.

Weiller

B.H.

Wasserman

E.P.

Bergman

R.G.

Moore

C.B.

Pimentel

G.C.

. “Time-Resolved IR Spectroscopy in Liquid Rare Gases: Direct Rate Measurement of an Intermolecular Alkane Carbon-Hydrogen Oxidative Addition Reaction”. J. Am. Chem. Soc. 1989. 111(21): 8288–8290.

29.

Bengali

A.A.

Schultz

R.H.

Moore

C.B.

Bergman

R.G.

. “Activation of the C–H Bonds in Neopentane and Neopentane-d12 by (η⁵-C₅(CH₃)₅)Rh(CO)₂: Spectroscopic and Temporal Resolution of Rhodium-Krypton and Rhodium-Alkane Complex Intermediates”. J. Am. Chem. Soc. 1994. 116(21): 9585–9589.

30.

Schultz

R.H.

Bengali

A.A.

Tauber

M.J.

Weiller

B.H.

Wasserman

E.P.

Kyle

K.R.

Moore

C.B.

Bergman

R.G.

. “IR Flash Kinetic Spectroscopy of C–H Bond Activation of Cyclohexane-d0 and -d12 by Cp*Rh(CO)₂ in Liquid Rare Gases: Kinetics, Thermodynamics, and Unusual Isotope Effect”. J. Am. Chem. Soc. 1994. 116(16): 7369–7377.

31.

McNamara

B.K.

Yeston

J.S.

Bergman

R.G.

Moore

C.B.

. “The Effect of Alkane Structure on Rates of Photoinduced C–H Bond Activation by Cp*Rh(CO)₂ in Liquid Rare Gas Media: An Infrared Flash Kinetics Study”. J. Am. Chem. Soc. 1999. 121(27): 6437–6443.

32.

George

M.W.

Hall

M.B.

Jina

O.S.

Portius

Sun

X.Z.

Towrie

Yang

Zaric

S.D.

. “Understanding the Factors Affecting the Activation of Alkane by Cp*Rh(CO)₂ (Cp' = Cp or Cp*)”. Proc. Natl. Acad. Sci. U. S. A. 2010. 107(47): 20178–20183.

33.

George

M.W.

Hall

M.B.

Portius

Renz

A.L.

Sun

X.-Z.

Towrie

Yang

. “Combined Experimental and Theoretical Investigation into C–H Activation of Cyclic Alkanes by Cp*Rh(CO)₂ (Cp = η5-C₅H₅ or η5-C₅Me₅)”. Dalton Trans. 2011. 40(8): 1751–1757.

34.

Pitts

A.L.

Wriglesworth

Sun

X.-Z.

Calladine

J.A.

Zaric

S.D.

George

M.W.

Hall

M.B.

. “Carbon-Hydrogen Activation of Cycloalkanes by Cyclopentadienylcarbonylrhodium—A Lifetime Enigma”. J. Am. Chem. Soc. 2014. 136(24): 8614–8625.

35.

Blake

Champness

N.R.

Easun

T.L.

Allan

D.R.

Nowell

George

M.W.

Jia

Sun

X.Z.

. “Photoreactivity Examined Through Incorporation in Metal-Organic Frameworks”. Nat. Chem. 2010. 2: 688–694.

36.

Nahhas

A.E.

Cannizzo

Mourik

F. v.

Blanco-Rodriguez

A.M.

Zális

Vlc̆ek

Jr. Chergui

. “Ultrafast Excited-State Dynamics of [Re(L)(CO)₃(bpy)]ⁿ Complexes: Involvement of the Solvent”. J. Phys. Chem. A. 2010. 114(22): 6361–6369.

37.

Archer

Weinstein

J.A.

. “Charge-Separated Excited States in Platinum(II) Chromophores: Photophysics, Formation, Stabilization and Utilization in Solar Energy Conversion”. Coord. Chem. Rev. 2012. 256(21-22): 2530–2561.

38.

Kuimova

M.K.

Alsindi

W.Z.

Blake

A.J.

Davies

E.S.

Lampus

D.J.

Matousek

McMaster

Parker

A.W.

Towrie

Sun

X.-Z.

Wilson

George

M.W.

. “Probing the Solvent Dependent Photophysics of fac-[Re(CO)₃(dppz-X₂)Cl] (dppz-X₂ = 11,12-X₂-dipyrido[3,2-a:2′,3′-c]phenazine); × = CH₃, H, F, Cl, CF₃)”. Inorg. Chem. 2008. 47(21): 9857–9869.

39.

Sun

Liu

Turro

. “Ultrafast Dynamics of the Low-Lying ³MLCT States of [Ru(bpy)₂(dppp₂)]²⁺“. J. Am. Chem. Soc. 2010. 132(16): 5594–5595.

40.

Turner

J.J.

. “Infrared Vibrational Band Shapes in Excited States”. Coord. Chem. Rev. 2002. 230(1-2): 212–223.

41.

George

M.W.

Turner

J.J.

. “Excited States of Transition Metal Complexes Studied by Time-Resolved Infrared Spectroscopy”. Coord. Chem. Rev. 1998. 177(1): 201–217.

42.

Kuimova

M.K.

Alsindi

W.Z.

Dyer

Grills

D.C.

Jina

O.S.

Matousek

Parker

A.W.

Portius

Sun

X.Z.

Towrie

Wilson

Yang

J.X.

George

M.W.

. “Using Picosecond and Nanosecond Time-Resolved Infrared Spectroscopy for the Investigation of Excited States and Reaction Intermediates of Inorganic Systems”. Dalton Trans. 2003. 21: 3996–4006.

43.

Dyer

Blau

W.J.

Coates

C.G.

Creely

C.M.

Gavey

J.D.

George

M.W.

Grills

D.C.

Hudson

Kelly

J.M.

Matousek

McGarvey

J.J.

McMaster

Parker

A.W.

Towrie

Weinstein

J.A.

. “The Photophysics of fac-[Re(CO)3(dppz)(py)]+ in CH₃CN: A Comparative Picosecond Flash Photolysis, Transient Infrared, Transient Resonance Raman and Density Functional Theoretical Study”. Photochem. Photobiol. Sci. 2003. 2(5): 542–554.

44.

Gamelin

D.R.

George

M.W.

Glyn

Grevels

F.-W.

Johnson

F.P.A.

Klotzbucher

Morrison

S.L.

Russell

Schaffner

Turner

J.J.

. “Structural Investigation of the Ground and Excited States of ClRe(CO)₃(4,4′-bipyridyl)₂ Using Vibrational Spectroscopy”. Inorg. Chem. 1994. 33(15): 3246–3250.