TY - JOUR

T1 - Photochemistry of dithiophosphinate Ni(S2P(i-Bu)2)2 complex in CCl4. Transient species and TD-DFT calculations

AU - Solovyev, Aleksey I.

AU - Mikheylis, Aleksandr V.

AU - Plyusnin, Victor F.

AU - Shubin, Aleksandr A.

AU - Grivin, Vjacheslav P.

AU - Larionov, Stanislav V.

AU - Tkachenko, Nikolai V.

AU - Lemmetyinen, Helge

N1 - Publisher Copyright: © 2019 Elsevier B.V.

PY - 2019/8/1

Y1 - 2019/8/1

N2 - Femtosecond spectroscopy and nanosecond laser flash photolysis were used to study the photophysical and photochemical transformations of the bis-diisobutyl-dithiophosphinate Ni(II)complex (Ni(S2P(i-Bu)2)2 = Ni(dtpi)2, where dtpi− ≡ −S2P(i-Bu)2)in CCl4 solutions. The radiation of second harmonic (405 nm)of Ti:Sapphire laser transfers the Ni(dtpi)2 complex to an excited 1LMCT state. Its decay in CCl4 is described by three exponents with time constants 0.58, 2.0 and ˜150 ps. The first process apparently involves the fast transitions from 1LMCT state to 3LMCT due to the intersystem crossing (ISC)and then to lower-lying “hot” 3LF (Ligand Field)state. The second time constant, most likely, corresponds to the vibrational cooling of this “hot” 3LF state. And the third slow process is the transition from 3LF state to ground state (1GS). The quantum yield of photochemical transformation under the 405 irradiation is close to zero, so the study of photochemistry was performed with a nanosecond flash photolysis at 308 nm. In this case an electron transfer from the excited Ni(dtpi)2 complex to a solvent molecule leads to the appearance of primary intermediate, the [ClNi(dtpi)(dtpi[rad])]complex, in which a dtpi[rad] radical is coordinated with a nickel ion via one sulfur atom. In the fast reaction with Ni(dtpi)2, this complex forms a long-lived dimer ClNi(dtpi)(dtpi[rad])[Ni(dtpi)2]. This intermediate for a few hundred microseconds decays in the reaction of recombination with the formation of (dtpi)2 disulphide and unstable ClNi(dtpi)complex. The insoluble NiCl2 salt falled in CCl4 as the sediment due to the reaction of two ClNi(dtpi)complexes. The quantum chemical calculations allowed to determine the geometry of the intermediate complexes arising in the photochemistry of Ni(S2P(i-Bu)2)2 complex.

AB - Femtosecond spectroscopy and nanosecond laser flash photolysis were used to study the photophysical and photochemical transformations of the bis-diisobutyl-dithiophosphinate Ni(II)complex (Ni(S2P(i-Bu)2)2 = Ni(dtpi)2, where dtpi− ≡ −S2P(i-Bu)2)in CCl4 solutions. The radiation of second harmonic (405 nm)of Ti:Sapphire laser transfers the Ni(dtpi)2 complex to an excited 1LMCT state. Its decay in CCl4 is described by three exponents with time constants 0.58, 2.0 and ˜150 ps. The first process apparently involves the fast transitions from 1LMCT state to 3LMCT due to the intersystem crossing (ISC)and then to lower-lying “hot” 3LF (Ligand Field)state. The second time constant, most likely, corresponds to the vibrational cooling of this “hot” 3LF state. And the third slow process is the transition from 3LF state to ground state (1GS). The quantum yield of photochemical transformation under the 405 irradiation is close to zero, so the study of photochemistry was performed with a nanosecond flash photolysis at 308 nm. In this case an electron transfer from the excited Ni(dtpi)2 complex to a solvent molecule leads to the appearance of primary intermediate, the [ClNi(dtpi)(dtpi[rad])]complex, in which a dtpi[rad] radical is coordinated with a nickel ion via one sulfur atom. In the fast reaction with Ni(dtpi)2, this complex forms a long-lived dimer ClNi(dtpi)(dtpi[rad])[Ni(dtpi)2]. This intermediate for a few hundred microseconds decays in the reaction of recombination with the formation of (dtpi)2 disulphide and unstable ClNi(dtpi)complex. The insoluble NiCl2 salt falled in CCl4 as the sediment due to the reaction of two ClNi(dtpi)complexes. The quantum chemical calculations allowed to determine the geometry of the intermediate complexes arising in the photochemistry of Ni(S2P(i-Bu)2)2 complex.

KW - Bis-diisobutyl-dithiophosphinate Ni(II)complex

KW - Intermediate particles

KW - Kinetics

KW - Laser flash photolysis

KW - Photolysis mechanism

KW - Quantum-chemical calculation

KW - MOLECULAR-STRUCTURE

KW - CRYSTAL

KW - CHARGE-TRANSFER PHOTOCHEMISTRY

KW - MIXED-LIGAND COMPLEXES

KW - DITHIOCARBAMATO COMPLEXES

KW - SPECTROSCOPY

KW - ULTRAFAST DYNAMICS

KW - N-10 NAOH GLASSES

KW - Bis-diisobutyl-dithiophosphinate Ni(II) complex

KW - ACETONITRILE

KW - PHOTOLYSIS

UR - http://www.scopus.com/inward/record.url?scp=85067953554&partnerID=8YFLogxK

U2 - 10.1016/j.jphotochem.2019.111857

DO - 10.1016/j.jphotochem.2019.111857

M3 - Article

AN - SCOPUS:85067953554

VL - 381

JO - Journal of Photochemistry and Photobiology A: Chemistry

JF - Journal of Photochemistry and Photobiology A: Chemistry

SN - 1010-6030

M1 - 111857

ER -