M. Photochromism and H. Systems;-dürr, , 1990.

H. Bouas-laurent, H. Dürr, and . Organic, Pure Appl. Chem, vol.73, pp.639-665, 2001.

J. C. Crano and R. J. Guglielmetti, Organic Photochromic and Thermochromic Compound, 1998.

M. Irie, Diarylethenes for memories and switches, Chem. Rev, vol.100, pp.1685-1716, 2000.

G. Berkovic, V. Krongauz, and V. Weiss, Spiropyrans and spirooxazines for memories and switches, Chem. Rev, vol.100, pp.1741-1753, 2000.

Y. Yokoyama, Fulgides for memories and switches, Chem. Rev, vol.100, pp.1717-1739, 2000.

H. Görner, C. Fischer, S. Gierisch, and J. Daub, Dihydroazulene/vinylheptafulvene photochromism: Effects of substituents, solvent, and temperature in the photorearrangement of dihydroazulenes to vinylheptafulvenes, J. Phys. Chem, vol.97, pp.4110-4117, 1993.

S. Jockusch, N. J. Turro, and F. R. Blackburn, Photochromism of 2H-naphto[1,2-b]pyrans: A spectroscopic investigation, J. Phys. Chem. A, vol.106, pp.9236-9241, 2002.

R. H. Mitchell, The metacyclophanediene-dihydropyrene photochromic ? switch, Eur. J. Org. Chem, pp.2695-2703, 1999.

, Molecules, vol.22, p.12, 2017.

P. Coppens, I. Novozhilova, and A. Kovalevsky, Photoinduced linkage isomers of transition-metal nitrosyl compounds and related complexes, Chem. Rev, vol.102, pp.861-883, 2002.

T. E. Bitterwolf, Photochemical nitrosyl linkage isomerism/metastable states, Coord. Chem. Rev, vol.250, pp.1196-1207, 2006.

J. J. Rack, Electron transfer triggered sulfoxide isomerization in ruthenium and osmium complexes, Coord. Chem. Rev, vol.253, pp.78-85, 2009.

B. A. Mcclure and J. J. Rack, Isomerization in photochromic ruthenium sulfoxide complexes, Eur. J. Inorg. Chem, pp.3895-3904, 2010.

S. O. Sylvester, J. M. Cole, and P. G. Waddell, Photoconversion bonding mechanism in ruthenium sulfur dioxide linkage photoisomers revealed by in situ diffraction, J. Am. Chem. Soc, vol.134, pp.11860-11863, 2012.

B. L. Feringa, The art of building small: From molecular switches to molecular motors, J. Org. Chem, vol.72, pp.6635-6652, 2007.

K. Szaci?owski, Digital Information Processing in Molecular Systems, Chem. Rev, vol.108, pp.3481-3548, 2008.

J. Andréasson and U. Pischel, Smart Molecules at Work-Mimicking Advanced Logic Operations, Chem. Soc. Rev, vol.39, pp.174-188, 2010.

W. Szymanski, J. M. Beierle, H. A. Kistemaker, W. A. Velema, and B. L. Feringa, Reversible photocontrol of biological systems by the incorporation of molecular photoswitches, Chem. Rev, vol.113, pp.6114-6178, 2013.

U. Pischel, J. Andréasson, D. Gust, and V. Pais, Information processing with molecules-Quo vadis? ChemPhysChem, vol.14, pp.28-46, 2013.

T. Kim, L. Zhu, R. O. Al-kaysi, and C. Bardeen, Organic photomechanical materials, ChemPhysChem, vol.15, pp.400-414, 2014.

A. M. Asadirad, S. Boutault, Z. Erno, and N. R. Branda, Controlling a polymer adhesive using light and a molecular switch, J. Am. Chem. Soc, vol.136, pp.3024-3027, 2014.

M. Boggio-pasqua, M. J. Bearpark, P. A. Hunt, and M. A. Robb, Dihydroazulene/vinylheptafulvene photochromism: A model for one-way photochemistry via a conical intersection, J. Am. Chem. Soc, vol.124, pp.1456-1470, 2002.

M. Boggio-pasqua, M. Ravaglia, M. J. Bearpark, M. Garavelli, and M. A. Robb, Can diarylethene photochromism be explained by a reaction path alone? A CASSCF study with model MMVB dynamics, J. Phys. Chem. A, vol.107, pp.11139-11152, 2003.

A. Migani, P. L. Gentili, F. Negri, M. Olivucci, A. Romani et al., The ring-opening reaction of chromenes: A photochemical mode-dependent transformation, J. Phys. Chem. A, vol.109, pp.8684-8692, 2005.

F. Maurel, J. Aubard, P. Millie, J. P. Dognon, M. Rajzmann et al., Quantum chemical study of the photocoloration reaction in the napthoxazine series, J. Phys. Chem. A, vol.110, pp.4759-4771, 2006.
URL : https://hal.archives-ouvertes.fr/hal-00083591

M. Boggio-pasqua, M. J. Bearpark, F. Ogliaro, and M. A. Robb, Photochemical reactivity of 2-vinylbiphenyl and 2-vinyl-1,3-terphenyl: The balance between nonadiabatic and adiabatic photocyclization, J. Am. Chem. Soc, vol.128, pp.10533-10540, 2006.

M. Boggio-pasqua, M. J. Bearpark, and M. A. Robb, Towards a mechanistic understanding of the photochromism of dimethyldihydropyrenes, J. Org. Chem, vol.72, pp.4497-4503, 2007.

G. Tomasello, F. Ogliaro, M. J. Bearpark, M. A. Robb, and M. Garavelli, Modeling the photophysics and photochromic potential of 1,2-dihydronaphthalene (DHN): A combined CASPT2//CASSCF-topological and MMVB-dynamical investigation, J. Phys. Chem. A, vol.112, pp.10096-10107, 2008.

G. Tomasello, M. J. Bearpark, M. A. Robb, G. Orlandi, and M. Garavelli, Significance of a zwitterionic state for fulgide photochromism: Implications for the design of mimics, Angew. Chem. Int. Ed, vol.49, pp.2913-2916, 2010.

A. Nenov, W. J. Schreier, F. O. Koller, M. Braun, R. De-vivie-riedle et al., Molecular model of the ring-opening and ring-closure reaction of a fluorinated indolylfulgide, J. Phys. Chem. A, vol.116, pp.10518-10528, 2012.

F. M. Raymo, Computational insights on the isomerization of photochromic oxazines, J. Phys. Chem. A, vol.116, pp.11888-11895, 2012.

F. Liu and K. Morokuma, Multiple pathways for the primary step of the spiropyran photochromic reaction: A CASPT2//CASSCF study, J. Am. Chem. Soc, vol.135, pp.10693-10702, 2013.

M. Boggio-pasqua and M. Garavelli, Rationalization and design of enhanced photoinduced cycloreversion in photochromic dimethyldihydropyrenes by theoretical calculations, J. Phys. Chem. A, vol.119, pp.6024-6032, 2015.
URL : https://hal.archives-ouvertes.fr/hal-01166087

C. Daniel and C. Gourlaouen, Chemical Bonding Alteration Upon Electronic Excitation in Transition Metal Complexes. Cood, Chem. Rev, vol.344, pp.131-149, 2017.

I. Ciofini, C. A. Daul, and C. Adamo, Phototriggered Linkage Isomerization in Ruthenium-Dimethylsulfoxyde Complexes: Insights from Theory, J. Phys. Chem. A, vol.107, pp.11182-11190, 2003.

A. J. Göttle, I. M. Dixon, F. Alary, J. Heully, and M. Boggio-pasqua, Adiabatic versus nonadiabatic photoisomerization in photochromic ruthenium sulfoxide complexes: a mechanistic picture from density functional theory calculations, J. Am. Chem. Soc, vol.133, pp.9172-9174, 2011.

O. P. Vieuxmaire, R. E. Piau, F. Alary, J. Heully, P. Sutra et al., Theoretical investigation of phosphinidene oxide polypyridine ruthenium(II) complexes: Toward the design of a new class of photochromic compounds, J. Phys. Chem. A, vol.117, 2013.
URL : https://hal.archives-ouvertes.fr/hal-00915275

A. J. Göttle, F. Alary, I. M. Dixon, J. Heully, and M. Boggio-pasqua, Unravelling the S?O linkage photoisomerization mechanisms in cis-and trans-[Ru(bpy) 2 (DMSO) 2 ] 2+ using density functional theory, Inorg. Chem, vol.53, pp.6752-6760, 2014.

H. Li, L. Zhang, Y. Wang, and X. Fan, Theoretical Studies on the Photoisomerization Mechanism of Osmium(II) Sulfoxide Complexes, RSC Adv, vol.5, pp.58580-58586, 2015.

H. Li, L. Zhang, I. Zheng, X. Li, X. Fan et al., Photoisomerization Mechanism of Ruthenium Sulfoxide Complexes: Role of the Metal-Centered Excited State in the Bond Rupture and Bond Construction Processes, Chem. Eur. J, vol.22, pp.14285-14292, 2016.

S. García, F. Juan;-alary, M. Boggio-pasqua, I. M. Dixon, I. Malfant et al., Establishing the Two-Photon Linkage Isomerization Mechanism in the Nitrosyl Complex trans, Inorg. Chem, vol.54, pp.8310-8318, 2015.

S. García, F. Juan;-alary, M. Boggio-pasqua, I. M. Dixon, and J. Heully, Is photoisomerization required for NO photorelease in ruthenium nitrosyl complexes?, J. Mol. Model, vol.22, 2016.

T. Woike and S. Haussühl, Infrared-Spectroscopic and Differential Scanning Calorimetric Studies of the Two Light-Induced Metastable States in K 2

, Solid State Commun, vol.86, pp.333-337, 1993.

D. V. Fomitchev and P. Coppens, X-ray Diffraction Analysis of Geometry Changes upon Excitation: The Ground-State and Metastable-State Structures of K

, Inorg. Chem, vol.35, pp.7021-7026, 1996.

D. V. Fomitchev, P. Coppens, T. Li, K. A. Bagley, L. Chen et al., Photo-induced metastable linkage isomers of ruthenium nitrosyl porphyrins, Chem. Commun, 1999.

D. Silva, S. C. Franco, and D. W. , Metastable Excited State and Electronic Structure of, Spectrochim. Acta A, vol.55, pp.1515-1525, 1999.

S. I. Gorelsky and A. B. Lever, Metastable States of Ruthenium (II) Nitrosyl Complexes and Comparison with [Fe(CN) 5 NO] 2?, Int. J. Quantum Chem, vol.80, pp.636-645, 2000.

S. Ferlay, H. W. Schmalle, G. Francese, H. Stoeckli-evans, M. Imlau et al., Light-Induced Metastable States in Oxalatenitrosylruthenium(II) and Terpyridinenitrosylruthenium(II) Complexes, Inorg. Chem, vol.43, pp.3500-3506, 2004.

D. Schaniel, T. Woike, C. Boskovic, and H. Güdel, Evidence for two light-induced metastable states in Cl 3, Chem. Phys. Lett, vol.390, pp.347-351, 2004.

A. Zangl, P. Klüfers, D. Schaniel, and T. Woike, Photoinduced Linkage Isomerism of {RuNO} 6 Complexes with Bioligands and Related Chelators, Dalton Trans, vol.6, pp.1034-1045, 2009.

D. Schaniel, B. Cormary, I. Malfant, L. Valade, T. Woike et al., Photogeneration of Two Metastable NO Linkage Isomers with High Populations of up to 76% in trans, Phys. Chem. Chem. Phys, vol.9, pp.1667-1678, 2007.

B. Cormary, I. Malfant, M. Buron-le-cointe, L. Toupet, B. Delley et al., (PF 6 ) 2 ·0.5H 2 O: A Model System for Structural Determination and Ab Initio Calculations of Photo-Induced Linkage NO Isomers, Acta Cryst. B, vol.65, pp.612-623, 2009.
URL : https://hal.archives-ouvertes.fr/hal-00665657

B. Cormary, S. Ladeira, K. Jacob, P. G. Lacroix, T. Woike et al., Malfant, I. Structural Influence on the Photochromic Response of a Series of Ruthenium Mononitrosyl Complexes, Inorg. Chem, vol.51, pp.7492-7501, 2012.

L. Khadeeva, W. Kaszub, M. Lorenc, I. Malfant, and M. Buron-le-cointe, Two-Step Photon Absorption Driving the Chemical Reaction in the Model Ruthenium Nitrosyl System, p.4
URL : https://hal.archives-ouvertes.fr/hal-01301351

, (PF 6 ) 2 ·1/2H 2 O, Inorg. Chem, vol.55, pp.4117-4123, 2016.

M. Tassé, H. S. Mohammed, C. Sabourdy, S. Mallet-ladeira, P. G. Lacroix et al., Synthesis, Crystal Structure, Spectroscopic, and Photoreactive Properties of a Ruthenium(II)-Mononitrosyl Complex, Polyhedron, vol.119, pp.350-358, 2016.

P. C. Ford, J. Bourassa, K. Miranda, B. Lee, I. Lorkovic et al., Photochemistry of Metal Nitrosyl Complexes. Delivery of Nitric Oxide to Biological Targets, Coord. Chem. Rev, vol.171, pp.185-202, 1998.

E. Tfouni, M. Krieger, B. R. Mcgarvey, D. W. Franco, and . Structure, Chemical and Photochemical Reactivity and Biological Activity of Some Ruthenium Amine Nitrosyl Complexes, Coord. Chem. Rev, vol.236, pp.57-69, 2003.

I. Szundi, M. J. Rose, I. Sen, A. A. Eroy-reveles, P. K. Mascharak et al., A New Approach for Studying Fast Biological Reactions Involving Nitric Oxide: Generation of NO Using Photolabile Ruthenium and Manganese NO Donors, Photochem. Photobiol, vol.82, pp.1377-1384, 2006.

T. E. Bitterwolf, Photolysis of [Ru(bipy) 2 (NO)Cl](PF 6 ) 2 in Frozen Ionic Glass Matrices. Evidence for Nitrosyl Linkage Isomerism and NO-Loss in a Physiologically Relevant Nitric Oxide Source, Inorg. Chem. Commun, vol.11, pp.772-773, 2008.

M. J. Rose and P. K. Mascharak, Photoactive Ruthenium Nitrosyls: Effects of Light and Potential Application as NO Donors, Coord. Chem. Rev, vol.252, pp.2093-2114, 2008.

M. J. Rose, N. L. Fry, R. Marlow, L. Hink, and P. K. Mascharak, Sensitization of Ruthenium Nitrosyls to Visible Light via Direct Coordination of the Dye Resorufin: Trackable NO Donors for Light-Triggered NO Delivery to Cellular Targets, J. Am. Chem. Soc, vol.130, pp.8834-8846, 2008.

H. Giglmeier, T. Kerscher, P. Klüfers, D. Schaniel, and T. Woike, Nitric-Oxide Photorelease and Photoinduced Linkage Isomerism on Solid, Dalton Trans, pp.9113-9116, 2009.

A. D. Ostrowski and P. C. Ford, Metal Complexes as Photochemical Nitric Oxide Precursors: Potential Applications in the Treatment of Tumors, Dalton Trans, pp.10660-10669, 2009.

N. L. Fry and P. K. Mascharak, Photoactive Ruthenium Nitrosyls as NO Donors: How to Sensitize Them toward Visible Light, Acc. Chem. Res, vol.44, pp.289-298, 2011.

J. Akl, I. Sasaki, P. G. Lacroix, I. Malfant, S. Mallet-ladeira et al., Comparative Photo-Release of Nitric Oxide from Isomers of Substituted Terpyridinenitrosyl-Ruthenium(II) Complexes: Experimental and Computational Investigations, Dalton Trans, vol.43, pp.12721-12733, 2014.

T. R. Deboer and P. K. Mascharak, Recent Progress in Photoinduced NO Delivery With Designed Ruthenium Nitrosyl Complexes, Adv. Inorg. Chem, vol.67, pp.145-170, 2015.

F. Talotta, J. Heully, F. Alary, I. M. Dixon, L. González et al., Linkage Photoisomerization Mechanism in a Photochromic Ruthenium Nitrosyl Complex: New Insights from a MS-CASPT2 Study, J. Chem. Theory Comput
URL : https://hal.archives-ouvertes.fr/hal-01684087

L. Freitag and L. González, Theoretical Spectroscopy and Photodynamics of a Ruthenium Nitrosyl Complex, Inorg. Chem, vol.53, pp.6415-6426, 2014.

M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria, M. A. Robb et al.,

I. Gaussian, , 2009.

E. Weinan, W. Ren, and E. Vanden-eijnden, Simplified and improved string method for computing the minimum energy paths in barrier-crossing events, J. Chem. Phys, vol.126, 2007.

A. D. Becke, Density-functional thermochemistry. III. The role of exact exchange, J. Chem. Phys, vol.98, pp.5648-5652, 1993.

S. Grimme, J. Antony, S. Ehrlich, and H. Krieg, A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu, J. Chem. Phys, vol.132, 2010.

A. Schäfer, H. Horn, and R. Ahlrichs, Fully optimized contracted Gaussian basis sets for atoms Li to Kr, J. Chem. Phys, vol.97, pp.2571-2577, 1992.

D. Andrae, U. Häußermann, M. Dolg, H. Stoll, and H. Preuß, Energy-adjusted ab initio pseudopotentials for the second and third row transition elements, Theor. Chim. Acta, vol.77, pp.123-141, 1990.

J. M. Martin and A. Sundermann, Correlation consistent valence basis sets for use with the Stuttgart-Dresden-Bonn relativistic effective core potentials: The atoms Ga-Kr and In-Xe, J. Chem. Phys, vol.114, pp.3408-3420, 2001.

J. Tao, J. P. Perdew, V. N. Staroverov, and G. E. Scuseria, Climbing the Density Functional Ladder: Nonempirical Meta-Generalized Gradient Approximation Designed for Molecules and Solids, Phys. Rev. Lett, vol.91, 2003.

A. D. Becke, A new mixing of Hartree-Fock and local density-functional theories, J. Chem. Phys, vol.98, pp.1372-1377, 1993.

S. Hirata and M. Head-gordon, Time-Dependent Density Functional Theory Within the Tamm?Dancoff Approximation, Chem. Phys. Lett, vol.314, pp.291-299, 1999.

F. Neese, An improvement of the resolution of the identity approximation for the formation of the Coulomb matrix, J. Comput. Chem, vol.24, pp.1740-1747, 2003.

F. Neese, F. Wennmohs, A. Hansen, and U. Becker, Efficient, approximate and parallel Hartree-Fock and hybrid DFT calculations. A 'chain-of-spheres' algorithm for the Hartree-Fock exchange, Chem. Phys, vol.356, pp.98-109, 2009.

F. Neese, The ORCA program system, WIREs Comput. Mol. Sci, vol.2012, pp.73-78

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