scholarly journals Vibrational Mode Coupling to Reverse Electron Transfer in (CN)5FeCNRu(NH3)5− in Solution

1999 ◽  
Vol 19 (1-4) ◽  
pp. 385-387
Author(s):  
Chengfei Wang ◽  
Boris Akhremitchev ◽  
Gilbert C. Walker
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Spectral Data ◽  
Infrared Spectra ◽  
High Frequency ◽  
Mode Coupling ◽  
Vibrational Mode ◽  
Time Resolved ◽  
Reverse Electron Transfer ◽  
Infrared Spectral

We present charge transfer absorption, resonance Raman and time-resolved infrared spectral data for (CN)5FeCNRu(NH3)5− in various solvents. The transient infrared spectra and anisotropies reveal both non-equilibrium vibrational populations of high frequency modes and local solvent heating.

Metal Halide Ammines. III. Thermal Analyses and Calorimetry of Fluorosilicate Ammines and Hydrates of Bivalent Metals. Infrared Spectra of the Ammines

1975 ◽  
Vol 53 (16) ◽  
pp. 2426-2429 ◽  
Author(s):  
Kashinath C. Patil ◽  
Etalo A. Secco
Keyword(s):  
Spectral Data ◽  
Infrared Spectra ◽  
Thermal Analyses ◽  
Calorimetric Data ◽  
Ammonia Loss ◽  
Bivalent Metal ◽  
Decomposition Reactions ◽  
Infrared Spectral ◽  
Bivalent Metals ◽  
And Calorimetry

Bivalent metal fluorosilicate ammines have been prepared. The thermal analyses of the dodecammines reveal the decomposition to occur via the pentammine and/or tetrammine. The final ammonia loss is concomitant with fluorosilicate decomposition. Calorimetric data are given for the decomposition reactions. Some fluorosilicate hydrates are included for comparison purposes.The infrared spectral data of the ammines are presented with their assignments.

scholarly journals Time-Resolved Spectroscopy of Photo-Induced Electron Transfer in Dinuclear and Tetranuclear Fe/Co Prussian Blue Analogues

2020 ◽  
Author(s):  
Jennifer Zimara ◽  
Hendrik Stevens ◽  
Rainer Oswald ◽  
Serhiy Demeshko ◽  
Sebastian Dechert ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Prussian Blue ◽  
Variable Temperature ◽  
Spin Transition ◽  
Acetonitrile Solution ◽  
Time Resolved ◽  
Thermally Induced ◽  
Prussian Blue Analogues ◽  
Charge Transfer Dynamics

The dynamics of photo-driven charge transfer-induced spin transition (CTIST) in two Fe/Co Prussian Blue Analogues (PBAs) is revealed by femtosecond IR and UV/vis pump-probe spectroscopy. Depending on temperature the known tetranuclear square-type complex [Co<sub>2</sub>Fe<sub>2</sub>(CN)<sub>6</sub>(tp*)<sub>2</sub>(4,4’-dtbbpy)<sub>4</sub>](PF<sub>6</sub>)<sub>2</sub> (<b>1</b>) exists in two electronic states. In acetonitrile solution at <240 K the low temperature (<b>LT</b>) phase is prevalent consisting of low-spin Fe(II) and low-spin Co(III), [Fe<sup>II</sup><sub>LS</sub>Co<sup>III</sup><sub>LS</sub>]<sub>2</sub>. Temperature rise causes thermally induced CTIST towards the high temperature (<b>HT</b>) phase consisting of low-spin Fe(III) and high-spin Co(II), [Fe<sup>III</sup><sub>LS</sub>Co<sup>II</sup><sub>HS</sub>]<sub>2</sub>, being prevalent at >300 K. Photo-excitation into the intervalence charge transfer (IVCT) band of the <b>LT</b> phase at 800 nm induces electron transfer in one Fe-Co edge of PBA <b>1</b> and produces a [Fe<sup>III</sup><sub>LS</sub>Co<sup>II</sup><sub>LS</sub>] intermediate which by spin crossover (SCO) is stabilized within 400 fs to a long-lived (>1 ns) [Fe<sup>III</sup><sub>LS</sub>Co<sup>II</sup><sub>HS</sub>]. In contrast, IVCT excitation of the <b>HT</b> phase at 400 nm generates a [Fe<sup>II</sup><sub>LS</sub>Co<sup>III</sup><sub>HS</sub>] species with a lifetime of 3.6 ps. Subsequent back-electron transfer populates the vibrationally hot ground state, which thermalizes within 8 ps. The newly synthesized dinuclear PBA, [CoFe(CN)<sub>3</sub>(tp*)(pz*<sub>4</sub>Lut)]ClO<sub>4</sub> (<b>2</b>), provides a benchmark of the <b>HT</b> phase of <b>1</b>, i.e. [Fe<sup>III</sup><sub>LS</sub>Co<sup>II</sup><sub>HS</sub>], as verified by variable temperature magnetic susceptibility measurements and <sup>57</sup>Fe Mößbauer spectroscopy. The photo-induced charge transfer dynamics of PBA <b>2</b> indeed is almost identical to that of the <b>HT</b> phase of phase of PBA <b>1</b> with a lifetime of the excited [Fe<sup>II</sup><sub>LS</sub>Co<sup>III</sup><sub>HS</sub>] species of 3.8 ps.

Metal Halide Ammines. II. Thermal Analyses, Calorimetry and Infrared Spectra of Fluoride Ammines and Hydrates of Bivalent Metals

1972 ◽  
Vol 50 (4) ◽  
pp. 567-573 ◽  
Author(s):  
K. C. Patil ◽  
E. A. Secco
Keyword(s):  
Spectral Data ◽  
Infrared Spectra ◽  
Thermal Analyses ◽  
Metal Halide ◽  
Metal Fluoride ◽  
Bivalent Metal ◽  
Calorimetric Measurements ◽  
Infrared Spectral ◽  
Bivalent Metals ◽  
Experimental Values

Thermal analyses of bivalent metal fluoride ammines reveal that decomposition occurs in two or more steps. Calorimetric measurements along with related enthalpic values of the various decomposition steps are given.The infrared spectral data of the ammines and hydrates are compared with theoretical and some experimental values already in the literature.

scholarly journals Mimicking Natural Photosynthesis: Designing Ultrafast Photosensitized Electron Transfer into Multiheme Cytochrome Protein Nanowires

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2143
Author(s):  
Daniel R. Marzolf ◽  
Aidan M. McKenzie ◽  
Matthew C. O’Malley ◽  
Nina S. Ponomarenko ◽  
Coleman M. Swaim ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Model Systems ◽  
Covalent Attachment ◽  
Chemical Labeling ◽  
Covalent Bonds ◽  
Time Resolved ◽  
Redox Active ◽  
Dynamics Simulations ◽  
Ultrafast Charge Transfer

Efficient nanomaterials for artificial photosynthesis require fast and robust unidirectional electron transfer (ET) from photosensitizers through charge-separation and accumulation units to redox-active catalytic sites. We explored the ultrafast time-scale limits of photo-induced charge transfer between a Ru(II)tris(bipyridine) derivative photosensitizer and PpcA, a 3-heme c-type cytochrome serving as a nanoscale biological wire. Four covalent attachment sites (K28C, K29C, K52C, and G53C) were engineered in PpcA enabling site-specific covalent labeling with expected donor-acceptor (DA) distances of 4–8 Å. X-ray scattering results demonstrated that mutations and chemical labeling did not disrupt the structure of the proteins. Time-resolved spectroscopy revealed three orders of magnitude difference in charge transfer rates for the systems with otherwise similar DA distances and the same number of covalent bonds separating donors and acceptors. All-atom molecular dynamics simulations provided additional insight into the structure-function requirements for ultrafast charge transfer and the requirement of van der Waals contact between aromatic atoms of photosensitizers and hemes in order to observe sub-nanosecond ET. This work demonstrates opportunities to utilize multi-heme c-cytochromes as frameworks for designing ultrafast light-driven ET into charge-accumulating biohybrid model systems, and ultimately for mimicking the photosynthetic paradigm of efficiently coupling ultrafast, light-driven electron transfer chemistry to multi-step catalysis within small, experimentally versatile photosynthetic biohybrid assemblies.

Infrared Spectra of Trimethylamine-Carbon Monoxide-Borane and its Deuterated Derivatives

1974 ◽  
Vol 28 (5) ◽  
pp. 427-430 ◽  
Author(s):  
James C. Carter ◽  
George W. Luther ◽  
Alfred L. Moyé
Keyword(s):  
Carbon Monoxide ◽  
Low Temperature ◽  
Spectral Data ◽  
Infrared Spectra ◽  
Nmr Data ◽  
Infrared Spectral

Low temperature infrared spectral data are given for the adducts H3BC(O)N(CH3)3, D3BC(O)N(CH3)3, H3BC(O)N(CD)3)3)D3BC(O)N(CD3)3 over the range 3000 to 300 cm−1. Boron-11 NMR data are given for H3BCO and H3BC(O)N(CH3)3. The spectra allow the assignment of the structure of the adducts as [Formula: see text]

Structure of donor-acceptor complexes. X. Complexes of cyanoacetamide with Lewis acids

1969 ◽  
Vol 22 (7) ◽  
pp. 1381 ◽  
Author(s):  
RC Paul ◽  
SL Chadha
Keyword(s):  
Oxygen Atom ◽  
Spectral Data ◽  
Infrared Spectra ◽  
Lewis Acids ◽  
Far Infrared ◽  
Carbonyl Oxygen ◽  
Aluminium Chloride ◽  
Infrared Spectral ◽  
Donor Acceptor ◽  
Ionic Nature

Complexes of cyanoacetamide with aluminium chloride and bromide, anti- mony(V) chloride, boron(III) bromide, tin(IV) chloride and bromide, titanium(IV) chloride and bromide, and zirconium(IV) chloride have been prepared. The molar conductances of the complexes in nitrobenzene indicate their non-ionic nature. The infrared spectra indicate bonding of the metal halides to the carbonyl oxygen atom of the ligand. Metal- to-oxygen bonding also gets support from the far-infrared spectral data.

scholarly journals Time-Resolved Spectroscopy of Photo-Induced Electron Transfer in Dinuclear and Tetranuclear Fe/Co Prussian Blue Analogues

2020 ◽  
Author(s):  
Jennifer Zimara ◽  
Hendrik Stevens ◽  
Rainer Oswald ◽  
Serhiy Demeshko ◽  
Sebastian Dechert ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Charge Transfer ◽  
Prussian Blue ◽  
Variable Temperature ◽  
Spin Transition ◽  
Acetonitrile Solution ◽  
Time Resolved ◽  
Thermally Induced ◽  
Prussian Blue Analogues ◽  
Charge Transfer Dynamics

The dynamics of photo-driven charge transfer-induced spin transition (CTIST) in two Fe/Co Prussian Blue Analogues (PBAs) is revealed by femtosecond IR and UV/vis pump-probe spectroscopy. Depending on temperature the known tetranuclear square-type complex [Co<sub>2</sub>Fe<sub>2</sub>(CN)<sub>6</sub>(tp*)<sub>2</sub>(4,4’-dtbbpy)<sub>4</sub>](PF<sub>6</sub>)<sub>2</sub> (<b>1</b>) exists in two electronic states. In acetonitrile solution at <240 K the low temperature (<b>LT</b>) phase is prevalent consisting of low-spin Fe(II) and low-spin Co(III), [Fe<sup>II</sup><sub>LS</sub>Co<sup>III</sup><sub>LS</sub>]<sub>2</sub>. Temperature rise causes thermally induced CTIST towards the high temperature (<b>HT</b>) phase consisting of low-spin Fe(III) and high-spin Co(II), [Fe<sup>III</sup><sub>LS</sub>Co<sup>II</sup><sub>HS</sub>]<sub>2</sub>, being prevalent at >300 K. Photo-excitation into the intervalence charge transfer (IVCT) band of the <b>LT</b> phase at 800 nm induces electron transfer in one Fe-Co edge of PBA <b>1</b> and produces a [Fe<sup>III</sup><sub>LS</sub>Co<sup>II</sup><sub>LS</sub>] intermediate which by spin crossover (SCO) is stabilized within 400 fs to a long-lived (>1 ns) [Fe<sup>III</sup><sub>LS</sub>Co<sup>II</sup><sub>HS</sub>]. In contrast, IVCT excitation of the <b>HT</b> phase at 400 nm generates a [Fe<sup>II</sup><sub>LS</sub>Co<sup>III</sup><sub>HS</sub>] species with a lifetime of 3.6 ps. Subsequent back-electron transfer populates the vibrationally hot ground state, which thermalizes within 8 ps. The newly synthesized dinuclear PBA, [CoFe(CN)<sub>3</sub>(tp*)(pz*<sub>4</sub>Lut)]ClO<sub>4</sub> (<b>2</b>), provides a benchmark of the <b>HT</b> phase of <b>1</b>, i.e. [Fe<sup>III</sup><sub>LS</sub>Co<sup>II</sup><sub>HS</sub>], as verified by variable temperature magnetic susceptibility measurements and <sup>57</sup>Fe Mößbauer spectroscopy. The photo-induced charge transfer dynamics of PBA <b>2</b> indeed is almost identical to that of the <b>HT</b> phase of phase of PBA <b>1</b> with a lifetime of the excited [Fe<sup>II</sup><sub>LS</sub>Co<sup>III</sup><sub>HS</sub>] species of 3.8 ps.

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