Charge transfer photochemistry of quadruply bonded ditungsten halophosphine complexes

Hsu, Tsui-Ling C.; Engebretson, Daniel; Helvoigt, Sara A.; Nocera, Daniel G.

doi:10.1016/0020-1693(95)04582-1

Cited by 9 publications

(9 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This explanation of the relationship between cobalt(II), zirconium(IV), and pyridine is consistent with experimental descriptions of molecular charge transfer polyads . In cases where the bridging moiety only provides structural connections, the excitation directly from donor to acceptor is detectable, and the system is functionally a dyad. , In cases where coupling between donor and both bridge and acceptor is strong, excitations to both states are detectable . In cases where the bridge represents an accessible state and direct coupling between donor and acceptor is weak, the evidence of transfer was enhancement in transient signal from the acceptor species (e.g., fluorescence or transient absorption). − Spectra suggest that our system functions most closely according to this latter type, Co → Zr → pyr.…”

Section: Discussionsupporting

confidence: 82%

“…74 In cases where the bridging moiety only provides structural connections, the excitation directly from donor to acceptor is detectable, and the system is functionally a dyad. 75,76 In cases where coupling between donor and both bridge and acceptor is strong, excitations to both states are detectable. 77 In cases where the bridge represents an accessible state and direct coupling between donor and acceptor is weak, the evidence of transfer was enhancement in transient signal from the acceptor species (e.g., fluorescence or transient absorption).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Photoinduced Electron Transfer from ZrOCo Binuclear Light Absorber to Pyridine Elucidated by Transient Optical and Infrared Spectroscopy

2018

View full text Add to dashboard Cite

All-inorganic heterobinculear units can be excited to a metal-to-metal charge transfer (MMCT) state by visible and ultraviolet light, and form the core of multicomponent artificial photosystems that rely on conjugated molecular wires to transmit electrons and holes across ultrathin silica separation membranes to catalytic sites. To understand electron transfer from a heterobinuclear unit to an organic molecule, model systems consisting of pyridine interacting with Zr IV OCo II or Ti IV OCo II sites on silica nanoparticles were assembled and spectroscopically characterized.Transient optical absorption spectroscopy combined with infrared analysis revealed that visible light excitation of assemblies in which pyridine interacts with the Zr center of the ZrOCo unit results in sub-10 nanosecond separation by electron transfer to the organic moiety. Rapid-scan FT-IR spectroscopy supported by density functional theory confirmed the identity of the pyridine radical anion charge-separated state. This state shows a lifetime of 220 (±60) ms prior to complete recovery of the initial state, suggesting spin crossover along the electron transfer path.No hole transfer from excited Zr IV OCo II  Zr III OCo III to pyridine is observed. The rectifying charge transfer behavior is an important design aspect for developing efficient artificial photosystems.

show abstract

Section: Discussionsupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

Photoinduced Electron Transfer from ZrOCo Binuclear Light Absorber to Pyridine Elucidated by Transient Optical and Infrared Spectroscopy

2018

View full text Add to dashboard Cite

show abstract

“…The luminescence lifetimes (upon excitation of the low-energy visible band) of the M 2 Cl 4 (PMe 3 ) 4 species have been previously measured to be 140 ns for M = Mo (in 2-methylpentane, φ = 0.26) and 41 and 50 ns for M = W (in dichloromethane and benzene, respectively), while we suspect that the electronic excited states of the other dimetal complexes decay at a faster rate . The data presented above do not distinguish between these two classes of compounds, and suggest that all these dimetal complexes have a significant nonradiative (thermal) contribution to their (1064 nm generated) excited-state decay.…”

Section: Discussionmentioning

confidence: 71%

Third-Order Nonlinear Optical Properties of Complexes with MM Triple and Quadruple Bonds (M = Mo, W) at 1064 nm by Degenerate Four-Wave Mixing

et al. 2002

View full text Add to dashboard Cite

Measurements of the third-order nonlinear optical responses of solutions of the metal-metal multiply bonded complexes Mo(2)(OPr(i))(6), W(2)(OBu(t))(6), M(2)(NMe(2))(6), M(2)(O(2)CBu(t))(4), and M(2)Cl(4)(PMe(3))(4) (M = Mo, W), using picosecond degenerate four-wave mixing at 1064 nm, are reported. These complexes display only very small instantaneous electronic polarizations when excited with cross-polarized beams. When the excitation beams are similarly polarized, a significant third-order optical response is detected, which is attributable to the formation of bulk thermal excitation gratings. Time-dependent measurements support this view.

show abstract

“…) C(15A) -O(2A) -Mo(1A)#1 118.01(13) C(15B) -O(1B) -Mo(1A) 116.06(13) O(1C) -Mo(1B) -Mo(1B)#2 90.99(4) Mo(1B)#2 -Mo(1B) -O(1D) 92.42(4) O(1C) -Mo(1B) -O(2D) 88.39(6) Mo(1B)#2 -Mo(1B) -O(2C)#2 92.27(4) O(1C) -Mo(1B) -O(2C)#2 176.61(6) O(1D) -Mo(1B) -O(2C)#2 90.54(2) Mo(1B)#2 -Mo(1B) -O(2D)#2 90.88(4) O(1C) -Mo(1B) -O(2D)#2 91.16(6) O(1D) -Mo(1B) -O(2D)#2 176.68(6) O(2C)#2 -Mo(1B) -O(2D)#2 89.72(6) C(15C) -O(1C) -Mo(1B) 118.44(14) C(15C) -O(2C) -Mo(1B)#2 116.87(13) C(15D) -O(1D) -Mo(1B) 117.11(14) C(15D) -O(2D) -Mo(1B)#2117.34(14) …”

mentioning

confidence: 99%

Observation of ¹MLCT and ³MLCT Excited States in Quadruply Bonded Mo₂ and W₂ Complexes

et al. 2005

View full text Add to dashboard Cite

The photophysical properties of the series of quadruply bonded M(2)(O(2)C-Ar)(4) [M = Mo, Ar = phenyl (ph), 1-naphthalene (1-nap), 2-naphthalene (2-nap), 9-anthracene (9-an), 1-pyrene (1-py), and 2-pyrene (2-py); M = W, Ar = ph, 2-nap] complexes were investigated. The lowest energy absorption of the complexes is attributed to a metal-to-ligand charge transfer (1)MLCT transition from the metal-based delta HOMO to the pi* O(2)C-Ar LUMO. The Mo(2)(O(2)C-Ar)(4) complexes exhibit weak short-lived emission (<10 ns) and a nonemissive, long-lived (40-76 mus) excited state detected by transient absorption spectroscopy. The short- and long-lived species are attributed to the (1)MLCT and (3)MLCT excited states, respectively, based on the large Stokes shift, vibronic progression in the low-temperature emission spectrum, and solvent dependence. Comparisons are made to the W(2)(O(2)C-Ar)(4) complexes, which are easier to oxidize and exhibit greater spin-orbit coupling than the Mo(2) systems. From the excited-state energy of the emissive (1)MLCT state and the electrochemical properties of the complexes, it is predicted that this excited state should be a powerful reducing agent. The crystal and molecular structure of Mo(2)(O(2)C-9-an)(4) is also reported together with electronic structure calculations employing density functional theory. To our knowledge, this is the first observation of MLCT excited states in quadruply bonded complexes. In addition, the photophysical properties of the present systems parallel those of organic aromatic molecules and may be viewed as metal-mediated organics. The introduction of the M(2) delta orbital in the complexes in conjugation with the organic pi-system of the ligands affords the opportunity to tune the excited-state energies and redox potentials.

show abstract

Charge transfer photochemistry of quadruply bonded ditungsten halophosphine complexes

Cited by 9 publications

References 23 publications

Photoinduced Electron Transfer from ZrOCo Binuclear Light Absorber to Pyridine Elucidated by Transient Optical and Infrared Spectroscopy

Photoinduced Electron Transfer from ZrOCo Binuclear Light Absorber to Pyridine Elucidated by Transient Optical and Infrared Spectroscopy

Third-Order Nonlinear Optical Properties of Complexes with MM Triple and Quadruple Bonds (M = Mo, W) at 1064 nm by Degenerate Four-Wave Mixing

Observation of ¹MLCT and ³MLCT Excited States in Quadruply Bonded Mo₂ and W₂ Complexes

Contact Info

Product

Resources

About

Charge transfer photochemistry of quadruply bonded ditungsten halophosphine complexes

Cited by 9 publications

References 23 publications

Photoinduced Electron Transfer from ZrOCo Binuclear Light Absorber to Pyridine Elucidated by Transient Optical and Infrared Spectroscopy

Photoinduced Electron Transfer from ZrOCo Binuclear Light Absorber to Pyridine Elucidated by Transient Optical and Infrared Spectroscopy

Third-Order Nonlinear Optical Properties of Complexes with MM Triple and Quadruple Bonds (M = Mo, W) at 1064 nm by Degenerate Four-Wave Mixing

Observation of 1MLCT and 3MLCT Excited States in Quadruply Bonded Mo2 and W2 Complexes

Contact Info

Product

Resources

About

Observation of ¹MLCT and ³MLCT Excited States in Quadruply Bonded Mo₂ and W₂ Complexes