Third-Generation W(CNAr)6 Photoreductants (CNAr = Fused-Ring and Alkynyl-Bridged Arylisocyanides).

Homoleptic tungsten(0) arylisocyanides possess photophysical and photochemical properties that rival those of archetypal ruthenium(II) and iridium(III) polypyridine complexes. Previous studies established that extending the π-system of 2,6-diisopropylphenylisocyanide (CNDipp) by coupling aryl substituents para to the isocyanide functionality results in W(CNDippAr)6 oligoarylisocyanide complexes with greatly enhanced metal-to-ligand charge transfer (MLCT) excited-state properties relative to those of W(CNDipp)6. Extending electronic modifications to delineate additional design principles for this class of photosensitizers, herein we report a series of W(CNAr)6 compounds with naphthalene-based fused-ring (CN-1-(2-iPr)-Naph) and CNDipp-based alkynyl-bridged (CNDippCCAr) arylisocyanide ligands. Systematic variation of the secondary aromatic system in the CNDippCCAr platform provides a straightforward method to modulate the photophysical properties of W(CNDippCCAr)6 complexes, allowing access to an extended range of absorption/luminescence profiles and highly reducing excited states, while maintaining the high molar absorptivity MLCT absorption bands, high photoluminescence quantum yields, and long excited-state lifetimes of previous W(CNAr)6 complexes. Notably, W(CN-1-(2-iPr)-Naph)6 exhibits the longest excited-state lifetime of all W(CNAr)6 complexes explored thus far, highlighting the potential benefits of utilizing fused-ring arylisocyanide ligands in the construction of tungsten(0) photoreductants.

[1]  O. Wenger,et al.  Excited-State Relaxation in Luminescent Molybdenum(0) Complexes with Isocyanide Chelate Ligands , 2020, Inorganics.

[2]  O. Wenger,et al.  Recent progress in the development of transition-metal based photoredox catalysts , 2020 .

[3]  Jing-lan Kan,et al.  A palladium-carbon-connected organometallic framework and its catalytic application. , 2019, Chemical communications.

[4]  O. Wenger,et al.  Long-Lived, Strongly Emissive, and Highly Reducing Excited States in Mo(0) Complexes with Chelating Isocyanides. , 2019, Journal of the American Chemical Society.

[5]  F. Castellano,et al.  Photophysical Processes in Rhenium(I) Diiminetricarbonyl Arylisocyanides Featuring Three Interacting Triplet Excited States. , 2019, Inorganic chemistry.

[6]  Chunying Duan,et al.  Mixed-Ligand Metal–Organic Framework for Two-Photon Responsive Photocatalytic C–N and C–C Coupling Reactions , 2018, ACS Catalysis.

[7]  C. Ko,et al.  Design of Luminescent Isocyano Rhenium(I) Complexes: Photophysics and Effects of the Ancillary Ligands. , 2018, Inorganic chemistry.

[8]  O. Wenger.  Photoactive Complexes with Earth-Abundant Metals. , 2018, Journal of the American Chemical Society.

[9]  O. Wenger,et al.  Luminescent complexes made from chelating isocyanide ligands and earth-abundant metals. , 2017, Dalton transactions.

[10]  H. Gray,et al.  Two-photon spectroscopy of tungsten(0) arylisocyanides using nanosecond-pulsed excitation. , 2017, Dalton transactions.

[11]  O. Wenger,et al.  Chromium(0), Molybdenum(0), and Tungsten(0) Isocyanide Complexes as Luminophores and Photosensitizers with Long-Lived Excited States. , 2017, Angewandte Chemie.

[12]  O. Wenger,et al.  A Tris(diisocyanide)chromium(0) Complex Is a Luminescent Analog of Fe(2,2'-Bipyridine)32. , 2017, Journal of the American Chemical Society.

[13]  J. McCusker,et al.  The photophysics of photoredox catalysis: a roadmap for catalyst design. , 2016, Chemical Society reviews.

[14]  O. Wenger,et al.  A Molybdenum(0) Isocyanide Analogue of Ru(2,2'-Bipyridine)3 (2+) : A Strong Reductant for Photoredox Catalysis. , 2016, Angewandte Chemie.

[15]  Hui Chao,et al.  Two-photon luminescent metal complexes for bioimaging and cancer phototherapy , 2016 .

[16]  H. Gray,et al.  Electronic Excited States of Tungsten(0) Arylisocyanides. , 2015, Inorganic chemistry.

[17]  H. Gray,et al.  Bespoke photoreductants: tungsten arylisocyanides. , 2015, Journal of the American Chemical Society.

[18]  G. Sheldrick.  Crystal structure refinement with SHELXL , 2015, Acta crystallographica. Section C, Structural chemistry.

[19]  James D. Blakemore,et al.  Generation of powerful tungsten reductants by visible light excitation. , 2013, Journal of the American Chemical Society.

[20]  D. MacMillan,et al.  Visible light photoredox catalysis with transition metal complexes: applications in organic synthesis. , 2013, Chemical reviews.

[21]  Andreas F. Rausch,et al.  The triplet state of organo-transition metal compounds. Triplet harvesting and singlet harvesting for efficient OLEDs , 2011 .

[22]  Qiang Zhao,et al.  Phosphorescent heavy-metal complexes for bioimaging. , 2011, Chemical Society reviews.

[23]  S. Toyota.  Rotational isomerism involving acetylene carbon. , 2010, Chemical reviews.

[24]  Anders Hagfeldt,et al.  Dye-sensitized solar cells. , 2010, Chemical reviews.

[25]  P. Müller.  Practical suggestions for better crystal structures , 2009 .

[26]  S. Bernhard,et al.  Synthetically tailored excited states: phosphorescent, cyclometalated iridium(III) complexes and their applications. , 2006, Chemistry.

[27]  P. Fanwick,et al.  REACTIVITY OF A TUNGSTEN(II) ARYLOXIDE WITH ISOCYANIDES AND ISOCYANATES , 1997 .

[28]  P. A. Anderson,et al.  Effect of Delocalization and Rigidity in the Acceptor Ligand on MLCT Excited-State Decay. , 1996, Inorganic chemistry.

[29]  S. Boyde,et al.  Influence of electronic delocalization in metal-to-ligand charge transfer excited states , 1995 .

[30]  S. Lippard,et al.  The 15 years of reductive coupling: what have we learned? , 1993 .

[31]  Corwin Hansch,et al.  A survey of Hammett substituent constants and resonance and field parameters , 1991 .

[32]  L. Lunazzi,et al.  Conformational studies by dynamic NMR. 40. Conformational atropoisomerism in highly hindered naphthylamines , 1991 .

[33]  G. Sheldrick.  Phase annealing in SHELX-90: direct methods for larger structures , 1990 .

[34]  Vincenzo Balzani,et al.  Ru(II) polypyridine complexes: photophysics, photochemistry, eletrochemistry, and chemiluminescence , 1988 .

[35]  R. Marcus,et al.  Electron transfers in chemistry and biology , 1985 .

[36]  B. P. Sullivan,et al.  Application of the energy gap law to the decay of charge transfer excited states, solvent effects , 1982 .

[37]  R. M. Richman,et al.  Photochemistry of Metal-Isocyanide Complexes and Its Possible Relevance to Solar Energy Conversion , 1978 .

[38]  P. Treichel,et al.  Electrochemical studies on [Mn(CNR)6]+ complexes , 1977 .

[39]  H. Gray,et al.  Excited-state reactivity patterns of hexakisarylisocyano complexes of chromium(0), molybdenum(0), and tungsten(0) , 1977 .

[40]  G. W. Robinson,et al.  Theory of Electronic Energy Relaxation in the Solid Phase , 1962 .

[41]  F. Ansbacher,et al.  A Note on the Overlap Integral of two Harmonic Oscillator Wave Functions , 1959 .

[42]  J. J. Markham.  Interaction of Normal Modes with Electron Traps , 1959 .

[43]  Giacomo Bergamini,et al.  Photochemistry and Photophysics of Coordination Compounds: Ruthenium , 2007 .

[44]  A. Barbieri,et al.  Photochemistry and Photophysics of Coordination Compounds: Iridium , 2007 .

[45]  V. Balzani,et al.  Photochemistry and Photophysics of Coordination Compounds II , 2007 .

[46]  Vincenzo Balzani,et al.  Photochemistry and photophysics of coordination compounds , 2007 .

[47]  H. Gray,et al.  Electronic Structures and Spectra of Hexakisphenylisocyanide Complexes of Cr(0), Mo(0), W(0), Mn(I), and Mn(II) , 1976 .

[48]  R. Englman,et al.  The energy gap law for non-radiative decay in large molecules , 1970 .

[49]  R. Belcher,et al.  664. The preparation of some new substituted naphthylamines and naphthidines , 1958 .