skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: New Rh2 (II,II) Complexes for Solar Energy Applications: Panchromatic Absorption and Excited-State Reactivity

Journal Article · · Journal of the American Chemical Society
DOI:https://doi.org/10.1021/jacs.7b08489· OSTI ID:1430209

In this work, the new heteroleptic paddlewheel complexes cis-[Rh2(μ-form)2(μ-np)2][BF4]2, where form = p-ditolylformamidinate (DTolF) or p-difluorobenzylformamidinate (F-form) and np = 1,8-napthyridyine, and cis-Rh2(μ-form)2(μ-npCOO)2 (npCOO = 1,8-naphthyridine-2-carboxylate), were synthesized and characterized. The complexes absorb strongly throughout the ultraviolet (λmax = 300 nm, ε = 20 300 M–1 cm–1) and visible regions (λmax = 640 nm ε = 3500 M–1 cm–1), making them potentially useful new dyes with panchromatic light absorption for solar energy conversion applications. Ultrafast and nanosecond transient absorption and time-resolved infrared spectroscopies were used to characterize the identity and dynamics of the excited states, where singlet and triplet Rh2/form-to-naphthyridine, metal/ligand-to-ligand charge-transfer (ML-LCT) excited states were observed in all four complexes. The npCOO complexes exhibit red-shifted absorption profiles extending into the near-IR and undergo photoinitiated electron transfer to generate reduced methyl viologen, a species that persists in the presence of a sacrificial donor. The energy of the triplet excited state of each complex was estimated from energy-transfer quenching experiments using a series of organic triplet donors (E(3ππ*) from 1.83 to 0.78 eV). The singlet reduction (+0.6 V vs Ag/AgCl) potentials, and singlet and triplet oxidation potentials (-1.1 and -0.5 V vs Ag/AgCl, respectively) were determined. Finally, based on the excited-state lifetimes and redox properties, these complexes represent a new class of light absorbers with potential application as dyes for charge injection into semiconductor solar cells and in sensitizer-catalyst assemblies for photocatalysis that operate with irradiation from the ultraviolet to ~800 nm.

Research Organization:
The Ohio State Univ., Columbus, OH (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
SC0010542
OSTI ID:
1430209
Journal Information:
Journal of the American Chemical Society, Vol. 139, Issue 41; ISSN 0002-7863
Publisher:
American Chemical Society (ACS)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 28 works
Citation information provided by
Web of Science

References (48)

Solar radiation and human health journal November 2010
Finding the Way to Solar Fuels with Dye-Sensitized Photoelectrosynthesis Cells journal September 2016
Dye-Sensitized Solar Cells journal November 2010
Optimizing Dyes for Dye-Sensitized Solar Cells journal April 2006
Influence of Ancillary Ligands in Dye-Sensitized Solar Cells journal August 2016
Wireless Solar Water Splitting Using Silicon-Based Semiconductors and Earth-Abundant Catalysts journal September 2011
Accumulative Charge Separation for Solar Fuels Production: Coupling Light-Induced Single Electron Transfer to Multielectron Catalysis journal February 2015
Conversion of light to electricity by cis-X2bis(2,2'-bipyridyl-4,4'-dicarboxylate)ruthenium(II) charge-transfer sensitizers (X = Cl-, Br-, I-, CN-, and SCN-) on nanocrystalline titanium dioxide electrodes journal July 1993
Squaraine-sensitized composite of a reduced graphene oxide/TiO 2 photocatalyst: π–π stacking as a new method of dye anchoring journal January 2015
Near-infrared squaraine co-sensitizer for high-efficiency dye-sensitized solar cells journal January 2016
Porphyrin-sensitized solar cells journal January 2013
Highly efficient porphyrin-sensitized solar cells with enhanced light harvesting ability beyond 800 nm and efficiency exceeding 10% journal January 2014
Porphyrin Cosensitization for a Photovoltaic Efficiency of 11.5%: A Record for Non-Ruthenium Solar Cells Based on Iodine Electrolyte journal October 2015
Molecular Engineering of Phthalocyanine Sensitizers for Dye-Sensitized Solar Cells journal April 2014
Design of an Organic Chromophore for P-Type Dye-Sensitized Solar Cells journal July 2008
Cyclometalated Ruthenium Sensitizers Bearing a Triphenylamino Group for p-Type NiO Dye-Sensitized Solar Cells journal August 2013
Photophysical Properties of MM Quadruply Bonded Complexes Supported by Carboxylate Ligands, MM = Mo 2 , MoW, or W 2 journal November 2012
Directional charge transfer and highly reducing and oxidizing excited states of new dirhodium( ii , ii ) complexes: potential applications in solar energy conversion journal January 2014
Photophysical Properties of cis -Mo 2 Quadruply Bonded Complexes and Observation of Photoinduced Electron Transfer to Titanium Dioxide journal July 2014
Electronic influences of bridging and chelating diimine ligand coordination in formamidinate-bridged Rh2(II,II) dimers journal January 2016
A Novel Dirhodium Compound with Neutral, Bridging 9-Ethyladenine Ligands journal May 1997
NMR Chemical Shifts of Trace Impurities: Common Laboratory Solvents, Organics, and Gases in Deuterated Solvents Relevant to the Organometallic Chemist journal May 2010
SHELXT – Integrated space-group and crystal-structure determination journal January 2015
Excited-State Properties of Rh 2 (O 2 CCH 3 ) 4 (L) 2 (L = CH 3 OH, THF, PPh 3 , py) journal March 2001
Early Events in the Photochemistry of Aryl Azides from Femtosecond UV/Vis Spectroscopy and Quantum Chemical Calculations journal October 2006
Ultrafast Carbene−Carbene Isomerization journal March 2008
Electronic structure and spectra of ruthenium diimine complexes by density functional theory and INDO/S. Comparison of the two methods journal October 2001
Multiple Bonds between Metal Atoms. 3rd Edition Edited by F. Albert Cotton, Carlos A. Murillo and Richard A. Walton. journal April 2007
Synthesis and characterization of dirhodium(II,II) formamidinate complexes containing short-bite nitrogen ligands journal February 2003
Electronic structure of phosphine adducts of tetrakis(carboxylato) dirhodium(II). Pronounced influence of axial ligands journal September 1981
Electronic structure of the rhodium-rhodium bond in dirhodium tetracarboxylates by a study of electronic spectra of neutral molecules and their cation radicals journal January 1983
Metal-metal bond in binuclear rhodium(II) acetate monohydrate journal March 1970
A combined magnetic circular dichroism and density functional theory approach for the elucidation of electronic structure and bonding in three- and four-coordinate iron( ii )–N-heterocyclic carbene complexes journal January 2015
The Mayer bond order as a tool in inorganic chemistry† journal January 2001
Ultrafast Fluorescence Detection in Tris(2,2‘-bipyridine)ruthenium(II) Complex in Solution:  Relaxation Dynamics Involving Higher Excited States journal July 2002
Intersystem crossing in transition metal complexes journal August 2006
Photoinduced charge separation and recombination kinetics in a dimeric iridium(I) complex with covalently bound alkyl-pyridinium acceptors journal October 1987
Structural Control of 1 A 2u -to- 3 A 2u Intersystem Crossing in Diplatinum(II,II) Complexes journal August 2012
Excited-state decay processes of binuclear rhodium(I) isocyanide complexes journal April 1993
Detection of the Singlet and Triplet MM δδ* States in Quadruply Bonded Dimetal Tetracarboxylates (M = Mo, W) by Time-Resolved Infrared Spectroscopy journal November 2011
Vibrational coherence in the excited state dynamics of Cr(acac)3: probing the reaction coordinate for ultrafast intersystem crossing journal January 2010
Investigating interfacial electron transfer in dye-sensitized NiO using vibrational spectroscopy journal January 2017
The absolute energy positions of conduction and valence bands of selected semiconducting minerals journal March 2000
Photoinduced hole injection in semiconductor-coordination compound systems journal February 2013
Electron injection dynamics in dye-sensitized semiconductor nanocrystalline films journal December 2014
New Photovoltaic Devices Based on the Sensitization of p-type Semiconductors: Challenges and Opportunities journal August 2010
Electrochemistry of the viologens journal January 1981
Excited State Dynamics of Methyl Viologen. Ultrafast Photoreduction in Methanol and Fluorescence in Acetonitrile journal June 2001

Cited By (5)

Photocatalytic H 2 production by dirhodium( ii , ii ) photosensitizers with red light journal January 2018
Unbridged Rh( ii )–Rh( ii ) complexes of N-heterocyclic carbenes and reactions with O 2 to form dirhodium( μη 1 : η 1 -O 2 ) complexes journal January 2019
One-step synthesis of ball-shaped metal complexes with a main absorption band in the near-IR region journal November 2019
Two Four‐Coordinate and Seven‐Coordinate Co II Complexes Based on the Bidentate Ligand 1, 8‐Naphthyridine Showing Slow Magnetic Relaxation Behavior journal December 2019
Electron injection into titanium dioxide by panchromatic dirhodium photosensitizers with low energy red light journal January 2019


Figures / Tables (8)