J. Phys. Chem. 1996, 100, 3075-3083
3075
Time-Resolved Resonance Raman and Transient Absorption Studies on Water-Soluble Copper(II) Porphyrins Sae Chae Jeoung and Dongho Kim* Spectroscopy Laboratory, Korea Research Institute of Standards and Science, Taejon 305-600, Korea
Dae Won Cho† and Minjoong Yoon* Department of Chemistry, Chungnam National UniVersity, Taejon 305-764, Korea ReceiVed: April 7, 1995; In Final Form: October 12, 1995X
Transient Raman and absorption spectroscopic investigations were carried out on copper(II) tetrakis(psulfonatophenyl)porphyrin (CuIITSPP) and copper(II) tetrakis(4-N-methylpyridyl)porphyrin (CuII(TMpy-P4)) in water, dioxane, and the mixed solvents to examine the exciplex formation of these water-soluble porphyrins with the solvents. We explained the nature of exciplex in terms of a photoinduced axial ligation with the solvent molecules. We demonstrated that the excited state lifetimes of copper(II) porphyrins are predominantly responsible for the observation of new transient Raman bands corresponding to the exciplex formation with the solvent molecules in the nanosecond transient Raman spectra. The addition of oxygen-containing solvents such as dioxane and tetrahydrofuran to the aqueous copper(II) porphyrin solutions induces an increase in the lifetimes of the transient species and consequently results in the observation of the transient Raman bands contributed by these exciplex species in the nanosecond transient Raman spectra. On the basis of a photokinetic scheme for the excited water-soluble copper(II) porphyrins in the water/dioxane mixed solvents, we have tried to provide further information on the ligand binding affinity of photoexcited water-soluble copper(II) porphyrins in the water/dioxane mixed solvents.
Introduction Copper(II) porphyrins have been a subject of intense investigations1-25 because of their peculiar photophysical properties, which stem from the interaction of the half-filled dx2-y2 orbital with a π-electronic system of the porphyrin ring. As a result of coupling, the ground and singlet excited 1(π,π*) states become doublet 2S(π,π*), whereas the excited triplet 3(π,π*) state is split into a tripdoublet 2T(π,π*) and a tripquartet 4T(π,π*). Besides (π,π*) transitions, two intramolecular charge transfer (CT) transitions between π orbitals of the porphyrin and the dx2-y2 orbital and an excited (d,d) state are possible, which are responsible for various photophysical processes in copper(II) porphyrins.1-5 To elucidate the deactivation mechanism of excited state copper(II) porphyrins, many experimental and theoretical studies have been carried out.1-13 Picosecond transient absorption measurements5a on copper(II) porphyrins have shown that the excited state lifetimes are reduced from >10 ns to e100 ps when an axial ligand is attached to a four-coordinated species to make a five-coordinated complex. This dramatic lifetime reduction has been ascribed to a ring-to-metal charge transfer (π,d) state, which drops in energy closer to or below the 2T/4T(π,π*) manifold upon the exciplex formation of copper(II) porphyrins with basic solvents such as pyridine or piperidine as an axial ligand. The temperature and solvent dependent picosecond and nanosecond flash photolysis experiments5b also suggested that the (π,d) CT state contributes significantly to the excited state dynamics of copper(II) porphyrins even in noncoordinating solvents, but the participation of a (d,π*) state cannot be ruled out. On the other hand, Kruglik et al.6 recently reported, based on the time resolved Raman, CARS, and picosecond transient * To whom correspondence should be addressed. † Present address: Department of Chemistry, Seonam University, Kwangchi-Dong, Namwon, Chunbuk 590-170, Korea. X Abstract published in AdVance ACS Abstracts, January 15, 1996.
0022-3654/96/20100-3075$12.00/0
absorption experiments, that the exciplex deactivation for copper(II) porphyrins proceeds via the excited (π,d) CT state in N-containing solvents (pyridine, piperidine, pyrrolidine) as well as in O-containing dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), while in O-containing tetrahydrofuran (THF), dioxane, and cyclohexanone the excited (d,d) state actively participates in the deactivation process. At the same time, de Paula et al.7 reported that a (d,π*) or (d,d) excited state lies close in energy to the 2T/4T(π,π*) manifold and is mainly responsible for the excited state dynamics upon the exciplex formation of copper(II) tetraphenylporphyrin (CuIITPP) with piperidine solvent as an axial ligand. In THF solvent the (π,d) and another excited state were suggested to contribute to the excited state dynamics by transient Raman measurements. Jeoung et al.,8 however, observed that the two transient excited states have participated in the decay dynamics in O- and N-containing solvents such as THF, dioxane, and pyridine. They suggested that the (π,d) CT states with and without an axial ligand are mainly responsible for the observed two transient states involved in the decay dynamics of excited copper(II) porphyrins in coordinating solvents. For theoretical calculations, three different types of calculations, IEH,10 XR,11 and PPP,12 did not lead to a decisive conclusion as to the nature of the state mainly responsible for the rapid quenching of the 2T/4T(π,π*) manifold, especially in the exciplex formation process with solvent molecules as axial ligands. Very recently, Stavrev and Zener13 reported that coordination as an axial ligand, such as pyridine, leads to an energy state below the Q band that is mostly a (d,d) state mixed with (π,d) CT character. Thus, it still seems controversial to the nature of the quenching state of copper(II) porphyrins. But, as shown by the experimental observations5-8 and theoretical calculation,10-13 two states seem to contribute simultaneously to the excited state dynamics of copper(II) porphyrins. © 1996 American Chemical Society
3076 J. Phys. Chem., Vol. 100, No. 8, 1996 In addition to the interesting but complicated excited state dynamics of copper(II) porphyrins, the interaction of porphyrins with nucleic acids has been another important aspect for watersoluble copper(II) porphyrins.14-25 The exciplex formation of a copper(II) tetrakis(4-N-methylpyridyl)porphyrin (CuII(TMpyP4)) complex with a variety of synthetic oligonucleotides as well as calf thymus DNA was attributed to a π-radical cation, which is induced by the intermolecular charge transfer from the highest occupied copper(II) porphyrin orbital into the lowest vacant orbital of a thymine residue.21-22 On the other hand, the time-resolved resonance Raman and the excitation profile investigations24,25 reported that the (d,d) state of the CuII(TMpyP4)-L five-coordinated complex (L ) CO group of thymine) is the main quenching deactivation channel for CuII(TMpy-P4) mixed with poly(dA-dT) in a phosphate buffer. Kruglik et al.25 also showed that the transient species for free CuII(TMpy-P4) in a phosphate buffer solution is short-lived (21 ( 3 ps), which is likely the 2T/4T(π,π*) manifold. But the mechanism for this behavior was not determined. To explore further the excited state dynamics and structural change of water-soluble copper(II) porphyrins, we have undertaken the time-resolved Raman and transient absorption measurements in aqueous solution because the exciplex can be formed by the interaction of watersoluble copper(II) porphyrins with water solvent molecules. Water contains oxygen atom that can function as an axial ligand like other O-containing organic solvents such as THF and dioxane. We examined the exciplex nature of water-soluble copper(II) porphyrins in water in terms of the photoinduced axial ligation with the solvent molecules. We have demonstrated that the two transient excited states have simultaneously contributed to the excited state dynamics of water-soluble copper(II) porphyrins in water. Our results provide further information on the mechanism of exciplex formation between water-soluble copper(II) porphyrins and nucleotides, where the excited state lifetime reduction induced by the axial ligation through exciplex formation is a major factor of the transient Raman bands probed by the transient nanosecond Raman technique. The 2T/4T(π,π*) manifold of copper(II) tetrakis(p-sulfonatophenyl)porphyrin (CuIITSPP) and CuII(TMpy-P4) in water is dynamically quenched by the axial ligation with water molecules with a resulting downshift of the (d,d) and/or CT states in energy and subsequent quenching of the 2T/4T(π,π*) manifold. Experimental Section CuIITSPP and CuII(TMpy-P4) were purchased from Porphyrin Products (Logan, UT) and used without further purification. Samples were prepared by mixing the metalloporphyrin in aqueous solution with the solvent of interest, keeping the porphyrin concentration constant. The final porphyrin concentration was adjusted to be approximately 10-5 M. All the experiments were performed by flowing the sample solutions through a glass capillary (0.8 mm i.d.) at a rate sufficient enough to ensure that each laser pulse encountered a fresh volume of the sample. The transient Raman spectra were obtained using the 416 and 436 nm pulses, generated by the hydrogen Raman shifting of the third (355 nm) and the second harmonics (532 nm), respectively, from a nanosecond Q-switched Nd:YAG laser. The Raman spectra were collected with an HR 640 spectrograph (Jobin-Yvon), a gated intensified photodiode array detector (Princeton Instruments IRY700), a delay generator (Stanford Research DG 535), and a pulse generator (Princeton Instruments FG135). For picosecond transient Raman spectra, the picosecond pulses at 436 nm were generated by an H2 Raman shifter
Jeoung et al. from 532 nm outputs (70 ps and 25 mJ/pulse) of a Nd:YAG regenerative amplifier (Continuum RGA-20) seeded by a modelocked Nd:YAG laser (Coherent Antares 76S). The ground state Raman spectra were recorded using the 457.9 nm line of a continuous wave (cw) Ar ion laser (Coherent Innova90), a Raman U1000 double monochromator (Jobin-Yvon), and photoncounting electronics (Hamamatsu). The absorption spectra were recorded on a Varian UV-visible spectrophotometer (Cary 5). The dual-beam femtosecond time-resolved transient absorption spectrometer consisted of a self mode-locked femtosecond Ti:sapphire laser (Spectra-Physics Tsunami), a Ti:sapphire regenerative amplifier (Quantronix) pumped by a Q-switched Nd:YLF laser, a pulse stretcher/compressor, and an optical detection system. The resulting amplified laser pulses had a pulse width of ∼150 fs and an average power of 300 mW at 1 kHz repetition rate. The amplified femtosecond optical pulses at 800 nm were split into two parts by a beam splitter. The pump pulses at 400 nm were generated by frequency doubling in a β-BBO crystal. These pulses were focused to a 1 mm diameter spot at the 1 mm path length quartz cell containing the sample. The other half of the beam at 800 nm travels along a variable optical delay line and was focused onto a quartz window to generate a white light continuum, which was again split into two parts: one for probing the transient and the other for the reference. The voltage signals from the two photodiodes were fed into a lock-in amplifier and then transferred to a personal computer for further processing. Results and Discussion Time-Resolved Transient Absorption Spectroscopy of CuIITSPP and CuII(TMpy-P4). To elucidate the excited state dynamics of CuIITSPP and CuII(TMpy-P4) in various solvents, we performed the picosecond transient absorption measurements by exciting with ca. 150 fs optical pulses at 400 nm and probing the absorbance change at 460 nm. The transient absorbance changes for both CuIITSPP and CuII(TMpy-P4) in water displayed first-order kinetics with lifetimes of ca. 23 and ca. 9 ps (closed circles in Figure 1), respectively. During the preparation of this paper, Kruglik et al.25 reported that from the picosecond transient absorption technique with a 10 ps resolution the transient species for CuII(TMpy-P4) in a phosphate buffer solution shows a lifetime of 21 ( 3 ps with an additional long-lived transient. These authors proposed that the shortlived transient species is the 2T/4T(π,π*) excited states and the long-lived one might be an excited (dz2,dx2-y2) state. Our kinetics of absorbance changes exhibits only one exponential decay without an evident presence of long-lived transients. Among many possibilities, the difference in lifetimes of excited CuII(TMpy-P4) in water is probably due to the phosphate buffer solution environment and the probe wavelength difference for the measurements by Kruglik et al.25 At this point, it is impossible to prefer one of these sets of different kinetics for the same molecular system. Although it is necessary to carry out additional experiments to clarify the discrepancies, the following picosecond transient Raman spectroscopic studies on CuII(TMpy-P4) in water reveal that water participates in the decay process of the excited state as a fifth ligand. For CuIITSPP in a water/dioxane mixture (6:4 in volume), the photoexcited transient exhibited a biexponential decay with lifetimes of ∼20 ps (a minor component that is about 20% in amplitude) and ∼100 ps (80% in amplitude) (open circles in Figure 1A), respectively. The emergence of the two different transient species in the water/dioxane mixture reveals that photoexcited CuIITSPP has a strong dependence of its lifetimes on the added solvent. The lifetime of the shorter component is
Water-Soluble Copper(II) Porphyrins
J. Phys. Chem., Vol. 100, No. 8, 1996 3077
Figure 2. Nanosecond transient RR spectra of CuIITSPP in water from 416 nm pulse excitation: (A) low-power; (B) high-power; (C) difference spectrum (B - A) with the proper subtraction factor.
Figure 1. Transient absorption decay profiles at 460 nm for CuIITSPP (A) and CuII(TMpy-P4) (B) in water (b) and in water/dioxane (6:4 in volume) solvents (O).
similar to that of excited CuIITSPP in water. To explain the above experimental results, it is not unreasonable to assume that these observations can be attributed to the exciplex formation of photoexcited CuIITSPP with water as an axial ligand, which participates in the decay process even in the mixture solvents. The other transient component with a lifetime of 100 ps is contributed by the exciplex formation of photoexcited CuIITSPP with dioxane. If the formation constants of fivecoordinated CuIITSPP complexes with water and dioxane are equal, the major component should be a CuIITSPP:water complex because the molar ratio of [dioxane]/[water] is ca. 0.13 in the used solution. However, the major component turned out to be CuIITSPP:dioxane. These findings can be explained by the differences in the complex formation constants in the excited state, i.e., the formation constant of CuIITSPP with dioxane is much larger than that with water. From a quantitative analysis, the former was found to be larger than the latter by a factor of ca. 33 (see below). A clue to the difference in the ratios of CuIITSPP:water and CuIITSPP:dioxane complexes was also seen in the ground state absorption spectra, in which an apparent red shift in the Soret band was observed with the addition of dioxane to the aqueous solution of CuIITSPP. A similar experiment has been carried out on CuII(TMpyP4) in the water/dioxane mixed solvent (6:4 in volume) (open circles in Figure 1B). However, in this case we hardly observed
the biexponential decay, of which one is due to the complexation of CuII(TMpy-P4) with water and the other with dioxane. Instead, only a single exponential decay with a 71 ps lifetime was detected. Thus, we can attribute the observed decay constant to complex formation by the interaction of photoexcited CuII(TMpy-P4) with dioxane solvent because the formation constant of CuII(TMPy-P4) with dioxane is believed to be much larger than that with water. Transient Raman Spectra of CuIITSPP and CuII(TMpyP4). It has been previously reported6-9 that CuIITPP and copper(II) octaethylporphyrin (CuIIOEP) exhibit a discernible downshift of the porphyrin skeletal modes in the excited states by nanosecond and picosecond transient Raman spectroscopies in N- and O-containing solvents such as pyridine, THF, and dioxane. Figure 2B presents the transient Raman spectrum of CuIITSPP in water obtained by high-power 416 nm single pulse excitation. In comparison to the spectrum of Figure 2A monitored by low-power excitation, an increase in the intensities of the Raman peaks at 1536 and 1340 cm-1 was easily noticeable. The emergence of these new Raman bands indicated that the water solvent, like THF and dioxane in the previous studies on CuIITPP and CuIIOEP,6-9 acts as an axial ligand for photoexcited CuIITSPP, and consequently lowers the energy of the quenching states such as the (d,d) or (π,d) CT states below that of the tripmultiplet 2T/4T(π,π*) states, serving as the main deactivation channel of photoexcited CuIITSPP in water. The Raman spectral features for ground state CuIITSPP were subtracted to yield the excited state Raman spectrum using a subtraction factor sufficient enough to avoid any negative features, and the difference Raman spectrum is displayed in Figure 2C. This difference spectrum gives the transient Raman bands at 1586, 1549, 1536, 1354, 1340, 1233, 1120, 1093, and 1080 cm-1, respectively. We have attempted to record the transient Raman spectrum with a two-color pump-probe technique with a time delay in order to obtain further information
3078 J. Phys. Chem., Vol. 100, No. 8, 1996
Jeoung et al. TABLE 1: Assignment of the Vibrational Modes (cm-1) of Excited State CuIITSPP in Water assignment
S0
CT1
shift
CT2
Ph4, ν(phenyl) ν2, ν(Cβ-Cβ) ν4, ν(pyr. half ring)sym ν1, ν(Cm-phenyl) ν5, δ(CβH)
1594 1556 1360 1238 1087
1586 1549 1354 1233 1080
-8 -7 -6 -5 -7
a 1536 1340 a a
shift -20 -20
a These Raman bands cannot be differentiated from those of CT 1 because of their equal positions.
Figure 3. Nanosecond transient RR spectra of CuIITSPP in KBr pellet from 416 nm pulse excitation: (A) low-power; (B)-(E) difference Raman spectra. The laser power in the spectra increases from bottom to top.
on the transients of CuIITSPP in water. However, this turned out to be a failure. This fact can be easily explained by the observation that the overall decay process of photoexcited CuIITSPP in water is faster than our nanosecond laser pulse width (3.5 ns). Indeed, the overall decay having ∼23 ps time constant was obtained from the transient absorption experiment of CuIITSPP in water. We also attempted to observe other transients, especially the tripmultiplet 2T/4T(π,π*) states, by monitoring the transient Raman spectrum of CuIITSPP in a noncoordinating solvent. But we cannot find any good noncoordinating solvents for CuIITSPP having enough solubility for Raman measurements. Therefore, a KBr pellet of CuIITSPP was prepared to monitor the transient Raman spectrum of photoexcited CuIITSPP without any solvent (ligation) effects (Figure 3). The ground state Raman spectrum of CuIITSPP in KBr pellet was almost identical to that in the solution phase. But the transient Raman spectrum probed by single pulse excitation at 416 nm gives Raman peaks at 1580, 1549, 1354, and 1232 cm-1, which correspond to, in part, the transient Raman peaks observed for excited CuIITSPP in water. Therefore, as in the cases of CuIITPP and CuIIOEP,8 the transient Raman peaks of CuIITSPP in water can be classified into two groups of transient states, CT1 and CT2, whose Raman frequencies are tabulated in Table 1. CT1 represents the low-lying quenching (d,d) or ring-to-metal (π,d) CT state of fourcoordinated copper(II) porphyrins, and CT2 represents the second quenching state associated with the higher affinity of copper(II) porphyrins for the ligands (solvents) in the transient state traversed in electronic deactivation. It was suggested that the axial ligand binding of a σ-donor solvent molecule to excited copper(II) porphyrins perturbs the molecular orbital of these porphyrins with a subsequent lowering of the energy of the quenching state below that of the 2T/4T(π,π*) multiplet states.5 This process results in a rapid radiationless deactivation through the quenching state, concurrent with an instant ligand release
while returning to the ground state. Since the oxygen atom of the THF solvent interacts as an axial ligand as exemplified by the separation of the FeIITPP(THF)2 complex,26 it is valid to assume that water can also act as an axial ligand through the oxygen atom for copper(II) porphyrins. We also recorded the transient Raman spectra of CuIITSPP in the dioxane/water mixed solvent to see the effect of the added oxygen-containing solvent on the photoexcited state decay dynamics. The ground state absorption spectrum of CuIITSPP in the dioxane/water mixture showed a slight red shift (5 nm) with an increase in the volume percentage of dioxane from 0 to 80%. This spectral change was attributed to the ligation of dioxane to CuIITSPP as an axial ligand in the ground state. However, no significant change in the ground state resonance Raman (RR) spectrum of CuIITSPP in the mixed solvent was found in comparison to that in aqueous solution. This observation suggested that the added dioxane solvent binds to CuIITSPP as an axial ligand in the ground state to only a small extent. At this point, the amount of five-coordinated CuIITSPP cannot be estimated because the molar extinction coefficient as well as the exact absorption spectrum of the five-coordinated CuIITSPP complex in the mixed solvent was not available. We carried out the transient RR spectroscopy on CuIITSPP in the mixed solvent with increasing dioxane or ethanol (Figures 4 and 5). In the mixed solvent, some new transient Raman bands increased with the addition of dioxane or ethanol. The increase of these new Raman bands can be explained in terms of two factors: (i) the selective occurrence of five-coordinated CuIITSPP formed by dioxane or ethanol solvents; (ii) the excited state dynamics of CuIITSPP in the mixed solvent. Although our results presented here cannot distinguish which factor is predominantly responsible for the appearance of the new transient Raman bands, the transient absorption spectrum unambiguously showed that the excited state dynamics of CuIITSPP plays an important role. In other words, the CuIITSPP transients formed in dioxane have longer lifetimes than those in water and consequently account for the increase of some new transient Raman bands probed by 3.5 ns laser pulses. In order to find out the precise Raman frequency shifts of smaller peaks at the shoulder of the intense Raman bands, the transient RR spectra were obtained by subtraction of the ground state Raman spectral features and simulation with Lorentzian line shape functions. The results for the ν4 mode in Figure 4 are displayed in Figure 6. With the results of the transient Raman spectra of CuIITSPP in water and in the KBr pellet, the Raman peaks at ca. 1355 and 1337 cm-1 can be attributed to the CT1 and CT2 states, respectively. From this simulation, we can draw a conclusion that the two types of transient states (the CT1 and CT2 states) contribute to the decay process of photoexcited CuIITSPP in the mixed solvent. Although it is difficult to know exactly the peak position and height of the CT1 state for each solvent composition, it is noticeable that the contribution of the Raman bands by the CT1 state is not as significant as that of the CT2 state under the same experimental conditions such as porphyrin concentration and laser power. Figure 7 shows the intensity ratio of the new transient Raman bands (the CT2 state)
Water-Soluble Copper(II) Porphyrins
Figure 4. Nanosecond transient RR spectra of CuIITSPP in dioxane/ water mixture solvents, with increasing relative portions of dioxane, from excitation with 416 nm pulses. The porphyrin concentrations and laser power were kept constant in the series of Raman spectra.
J. Phys. Chem., Vol. 100, No. 8, 1996 3079
Figure 6. Observed (points) and simulated (solid lines) transient Raman spectral features of the ν4 mode for CuIITSPP with increasing volume fraction of dioxane in the dioxane/water mixture solvent.
each other, the intensities of the transient Raman peaks of fivecoordinated CuIITSPP complexes with the oxygen-containing solvents increase in the following order:
CuIITSPP:water < CuIITSPP:ethanol < CuIITSPP:dioxane
Figure 5. Nanosecond transient RR spectra of CuIITSPP as a function of the relative portion of ethanol in ethanol/water mixture solvents. All the other experimental conditions are same as those for Figure 4.
relative to their corresponding ground state Raman ones in CuIITSPP. Considering that the Raman scattering efficiencies of the same modes for all the detected transients are similar to
For another water-soluble copper(II) porphyrin, CuII(TMpyP4), an attempt to obtain the transient Raman spectrum with 3.5 ns laser pulses was unsuccessful under any experimental condition, including the variaton of laser power and porphyrin concentration, presumably because photoexcited CuII(TMpyP4) in water is too short-lived to give the transient Raman spectrum with the nanosecond pulses. These observations are in good accordance with the findings of the transient absorption measurement in which photoexcited CuII(TMpy-P4) in water shows a lifetime of ∼9 ps. To gain further information on the decay process of photoexcited CuII(TMpy-P4) in water, we probed the transients by picosecond transient Raman spectroscopy, and their results are displayed in Figure 8. Although the signal-to-noise ratios of these spectra are not high because of a weak absorbance at 435 nm and the short lifetime of the transient state of CuII(TMpyP4) in water, the Raman peak intensities at 1550 and 1345 cm-1 apparently increase with an increase of the laser power. The observed peak positions of these new bands are in good agreement with those reported21-25 for the complex of the electronically excited CuII(TMpy-P4) with poly(dA-dT), calf thymus DNA, and a specific single-stranded polynucleotide. Thus, it is proposed that a similar exciplex formation of CuII(TMpy-P4) with water also occurs in the excited state. This observation indicates that the presence of a specific polynucleotide as well as its proper secondary structures is not a prerequisite for exciplex formation in CuII(TMpy-P4). Meanwhile, the excited state lifetime of this exciplex seems to play an important role in the observation of the transient Raman bands in the nanosecond transient Raman spectroscopy. We
3080 J. Phys. Chem., Vol. 100, No. 8, 1996
Figure 7. Measured (points) and simulated (solid lines) intensity ratios of some new transient Raman bands to the corresponding ground state Raman bands as a function of the concentration of the added solvents (dioxane or ethanol) to water: (b) ν2 and (O) ν4 for CuIITSPP in dioxane/water; (3) ν4 for CuIITSPP in ethanol/water; (9) ν2 and (0) ν4 for CuII(TMpy-P4) in the dioxane/water solvent system. The solid lines were calculated using the proposed mechanism and the measured rate constants mentioned in the text.
suggested that the addition of oxygen-containing solvents such as dioxane and THF to aqueous copper(II) porphyrins induces an increase in the lifetimes of excited copper(II) porphyrins and consequently results in the observation of some new bands in the nanosecond transient Raman spectra. The difference Raman spectrum was obtained by subtracting the Raman spectral features obtained under low power from that obtained under high power with a proper scaling factor and displayed in Figure 8D. The resulting difference spectrum in the range of the ν2 and ν4 modes, especially, has spectral features similar to those of other copper(II) porphyrins6-8,25 such as CuIITPP, CuIIOEP, and CuIITSPP in oxygen-containing solvents like THF, dioxane, and H2O. These observations led us to a conclusion that the nature of photoexcited CuII(TMpy-P4) in oxygen-containing solvents is not different from those of other copper(II) porphyrins. The nanosecond transient RR spectra of CuII(TMpy-P4) in solvents of varying composition were obtained under identical experimental conditions (laser power and porphyrin concentration) to avoid any possible experimental artifacts resulting from their changes. Figure 9 shows a series of transient Raman spectra with an increase of the partial mole fraction of dioxane. The intensity ratios of the new transient Raman bands at 1551 and 1348 cm-1 (the CT2 state) to their corresponding ground state ones are shown in Figure 7. It is interesting to note that the lifetime of excited CuII(TMpy-P4) in dioxane is longer than that in water, which was verified by the kinetic results from the time-resolved transient absorption measuremenst. This behavior enables us to monitor the transient Raman bands of
Jeoung et al.
Figure 8. Picosecond transient RR spectra of CuII(TMpy-P4) in water as a function of the incident laser power at 436 nm (spectra A-C). The difference Raman spectrum (C - A) is shown in spectrum D. The laser power in the spectra increases from (A) to (C).
Figure 9. Nanosecond transient RR spectra of CuII(TMpy-P4) in dioxane/water mixture solvents, with increasing relative portions of dioxane, from excitation with 416 nm pulses. The porphyrin concentration and laser power were kept constant in the series of Raman spectra.
CuII(TMpy-P4) by nanosecond pulse excitation with increasing amounts of dioxane solvent.27
Water-Soluble Copper(II) Porphyrins Photokinetic Scheme for Photoexcited CuIITSPP and CuII(TMpy-P4) in the Mixed Solvent. It is necessary to discuss the nature of the transient molecular species of copper(II) porphyrins before discussing the overall kinetics of the transient species. On the basis of the earlier work on CuIITPP and CuIIOEP in several coordinating and noncoordinating solvents,8 we can assign the observed transients for water-soluble copper(II) porphyrins to the intramolecular ring-to-metal (π,d) CT state associated with the solvent binding/release as an axial ligand accompanying a large core size expansion. Kruglik et al.,25 however, proposed that the transient species of water-soluble copper(II) porphyrins are assignable to the excited (dz2,dx2-y2) state of five-coordinated copper(II) porphyrins. They observed, however, only one type of transient species in the time-resolved resonance Raman (TR3) experiment, while the decay curve of absorbance changes in the transient absorption measurement is biphasic because of the presence of two transient species. Their proposal was based on the observation of behavior similar to that of the (d,d) states of nickel(II) porphyrins27,28 and fivecoordinated cobalt(III) porphyrins.29 Such similarities include the Raman frequency shifts of the porphyrin skeletal modes and the transient absorption spectra. In their investigations, they successfully explained some photophysical properties of copper(II) porphyrins. However, it is necessary to consider the spin multiplicities of the central metal of metalloporphyrins. It has been known that the lowest excited states of four-coordinated nickel(II) porphyrins27,28 and CoIIIOEP(CN)29 are 3(dz2,dx2-y2) and 3(dπ,dz2), respectively. Copper(II), however, has a d9 electronic configuration. If the excited (d,d) state is assignable to the main quenching state of copper(II) porphyrins, the spin state does not change relative to the ground state. Ake and Gouterman30 reported, from theoretical calculations, that additional ligation to NiIITPP without a change in spin state would not be expected to change the core size very much. Assuming that this statement also has validity in copper(II) porphyrins, the 2(d,d) excited state may not accomodate such large Raman frequency shifts because the spin multiplicity does not change. Furthermore, the excited state lifetimes of CuIIOEP in noncoordinating solvents were reported to be strongly dependent on the dielectric constants of the solvents (1050 ns in pentane Vs 100 ns in dichloromethane),5b while the lifetimes of nickel(II) porphyrins are almost constant with the variation of the dielectric constants of solvents.28b If the (d,d) state is predominantly responsible for the decay process of CuIIOEP, this state would be less sensitive to the solvent polarities than the ring-to-metal (π,d) CT state because the (d,d) state involves an electronic transition only in copper metal. In addition, the photoexcited deactivation dynamics for CuIIOEP and CuIITPP were reported to be different in noncoordinating solvents,5b where a difference in the inherent decay of the CT state may also contribute in addition to a difference in energy gap between the CT and 2T/4T (π,π*) states in these two porphyrin complexes. The lowest CT state probably is [a1u(π),d] for CuIIOEP and [a2u(π),d] for CuIITPP based on the types of the electrochemically generated π-cationic radicals.31 The internal and solvent reorganizations accompanying deactivation of these two CT states may not be the same probably because of the difference in the electron density distributions of the a1u(π) and a2u(π) orbitals. These arguments also support the idea that the CT state is probably more sensitive to the solvent nature, such as dielectric constants, and thus different excited state dynamics through the CT state from that of the (d,d) state can be anticipated. We also measured the S1(π,π*) state lifetimes for H2TPP in O- and N-containing solvents such as THF, pyridine, and piperidine, which turned out to be similar (∼10 ns) regardless of the solvents employed. This observation
J. Phys. Chem., Vol. 100, No. 8, 1996 3081 indicates that the S1(π,π*) state decay dynamics of porphyrins are not influenced by the solvent nature unless there is a ligand binding process in the ground and excited states. Kruglik et al.6 also reported that the deactivation of the exciplex of CuIIOEP formed by the interaction with the solvent is dependent on its electronic nature. The excited (π,d) CT state is mainly responsible for the deactivation in N-containing solvents (pyridine, piperidine, and pyrrolidine) as well as in O-containing solvents like DMF and DMSO. But the excited 2(d,d) state was suggested to be the main deactivation channel for copper(II) porphyrins in O-containing solvents (THF, dioxane, and cyclohexanone). On the other hand, de Paula7 reported that the transient Raman spectrum for CuIITPP with piperidine as a ligand is consistent with either a (d,d) or a metalto-ring (d,π*) CT excited state. In THF, two distinct excited states were observed7 in which one of them is assigned to either a (d,d) or a (d,π*) state, like in piperidine, and the other to a ring-to-metal (π,d) CT state. In our previous paper,8 the overall features of the transient Raman spectra for copper(II) porphyrins in both O-containing solvents like THF and dioxane and N-containing pyridine solvent are similar to each other even though the lifetimes of the transient species are very much dependent on the nature of solvent. These observations seem to support the idea that the exciplex species of copper(II) porphyrins formed in both O- and N-containing solvents have the same electronic nature. However, recent SCF/CI calculations on copper(II) porphyrin-pyridine12 revealed that the lowest excited state of the exciplex, of which the distance between the copper and nitrogen atoms of pyridine was set to be between 2.0 and 2.2 Å, is a mixture of the ring-to-metal (π,d) CT and (d,d) states. Thus, without any further direct experimental observations to resolve this contradiction, we could not absolutely determine the nature of the excited state that is mainly responsible for the observed exciplex formation/deactivation of copper(II) porphyrins with solvent molecules as axial ligands. Thus, as mentioned in the Introduction, the 2(d,d) and ring-to-metal (π,d) CT states probably contribute simultaneously to the deactivation dynamics of photoexcited copper(II) porphyrins. It is useful to have additional information on the decay mechanism of photoexcited copper(II) porphyrin in the water/ dioxane mixed solvent regardless of the electronic structure of the exciplex. A suitable mechanism should include at least four molecular species to explain the experimental observations: CuIIP, ground state copper(II) porphyrin, without coordination with the oxygen-based solvent; CuIIP*, the excited state copper(II) porphyrin produced by 416 nm pulse excitation, which is probably the tripmultiplet (2T/4T(π,π*)); CuIIPq, a transient fourcoordinated species (CT1); (CuIIP:solvent)q, a transient fivecoordinated species (CT2) with the solvent molecule, which is formed from CuIIP*. They are inter-related to each other by the following scheme, and their concentrations can also be derived from it: I0σ
CuIIP 98 CuIIP* k1
CuIIP* + H2O 98 (CuIIP:H2O)q k2
CuIIP* + dioxane 98 (CuIIP:dioxane)q k3
CuIIP* 98 CuIIPq
(1) (2)
(3) (4)
3082 J. Phys. Chem., Vol. 100, No. 8, 1996 k4
(CuIIP:H2O)q 98 CuIIP + H2O k5
(CuIIP:dioxane)q 98 CuIIP + dioxane k6
CuIIPq 98 CuIIP
Jeoung et al.
(5) (6) (7)
d[CuIIP*] ) I0σ[CuIIP] - k1[CuIIP*][H2O]dt k2[CuIIP*][dioxane] - k3[CuIIP*] (8) d[(CuIIP:H2O)q] ) k1[CuIIP*][H2O] - k4[(CuIIP:H2O)q] (9) dt d[(CuIIP:dioxane)q] ) k2[CuIIP*][dioxane] dt k5[(CuIIP:dioxane)q] (10) in which I0 and σ are the laser photon flux and the absorption cross section, respectively, and k1, k2, k3, k4, k5, and k6 are the rate constants. Our kinetics of transient absorbance changes were employed for the decay of the exciplex of (CuIIP:solvent)q; k4’s for CuIITSPP and CuII(TMpy-P4) were measured to be 4.4 × 1010 and 1.1 × 1011 s-1, respectively, and k5’s for CuIITSPP and CuII(TMpy-P4) to be 1.0 × 1010 and 1.4 × 1010 s-1, respectively. The ratio, R, of the Raman intensities between the ground state copper(II) porphyrin (CuIIP) and the transient state ((CuIIP: solvent)q) shown in Figure 7 is given, employing the Raman scattering efficiency j:
R)
jH2O[CuIIP:H2O)q] + jdio[(CuIIP:dioxane)q] jG[CuIIP]
(11)
The time-resolved transient absorption experiments clearly showed that all the observed lifetimes of the transient species are less than 100 ps with a negligible rise time. These facts provided a rationale for the steady state approximation in the further treatment of the experimental results obtained with our 3.5 ns laser pulses. After rearranging the steady state equations for all the species,
[Cu P*] )
I0σ[CuIIP]
II
k1[H2O] + k2[dioxane] + k3
[(CuIIP:H2O)q] )
k1[CuIIP*][H2O] k4
k2[CuIIP*][dioxane] [(CuIIP:dioxane)q] ) k5
route to form the CuIIPq species from CuIIP* seems to be less effective compared to the formation of the (CuIIP:solvent)q species because photoexcited copper(II) porphyrins readily form the exciplex with the solvent molecules as axial ligands.5a In addition, the energy state of the CuIIPq species was suggested to be comparable to or slightly higher than that of the 2T/4T(π,π*) states because CuIIPq and the 2T/4T(π,π*) state (CuIIP*) were simultaneously observed in the transient Raman spectra for CuIITPP in benzene (noncoordinating solvent).8 We can also derive another piece of information on the relative proportion of the channel that forms the CuIIPq species to one that forms the (CuIIP:solvent)q species from the Raman peak intensity ratio of these two species (Figure 6). The Raman intensity ratio was obtained from the simulation of the ν4 mode of CuIITSPP in the dioxane/water mixture solvents under the assumption that the Raman scattering efficiency of the CuIIPq species is not much different from that of the (CuIIP:solvent)q species. From these observations, it is not unreasonable to suppose that the value of k3 in the denominator of the eq 12 is not as significant as that of (k1[H2O] + k2[dioxane]). The previous picosecond transient absorption spectra of CuIITPP in toluene, pyridine, and piperidine5a showed only featureless broad absorptions that are characteristic of 2T/4T(π,π*) states without significant contributions from the CT or (d,d) states with lifetimes of ∼40 ns in toluene and e100 ps in pyridine and piperidine. This observation was explained by the suggestion that from photoexcited copper(II) porphyrins (CuIIP*) the formation of (CuIIP:solvent)q is more efficient than that of the CuIIPq species, and the decay of (CuIIP:solvent)q to the ground state is also efficient relative to the formation process. The relatively low extinction coefficient of the quenching state also contributes to the prevailing strong absorption of the 2T/4T(π,π*) manifold. From the previous transient absorption and Raman measurements,5,8 we can roughly estimate that the k1 and k2 processes are more efficient than that of k3 and that the k6 process is faster than that of k3 for water-soluble copper(II) porphyrins in dioxane/water mixed solvents. With the above experimental observations and interpretations, we can rewrite eq 11 by including the eqs 12-14 as follows:
jH2O
I0σ
R) 1+
(12)
(13)
]
(15)
k1[H2O] It is necessary to derive the limiting values of R from the experimental results as follows: jH2O 1
R0 ) lim R ) I0σ xf0
jG k4
(14)
In order to obtain valid information on the photochemical process from the available experimental results, it is important to transform eq 11 with experimental observables. At this point, it is difficult to extract the exact lifetime of the transient state (CuIIPq) with the experimental results shown in this work. From the nanosecond two-color TR3 results of CuIITPP in THF solvent from our laboratory (see Figure 2 in ref 8), however, we can estimate the lifetimes of both CuIIPq and (CuIIP:solvent)q species. Although it is difficult to determine precisely the lifetime for each species, the formation time and lifetime of the CuIIPq species seem to be comparable to or slightly longer than the decay time of (CuIIP:solvent)q species in THF. Also, the decay
[
1 jdiok2[dioxane] + k2[dioxane] k4 jH2Ok5k1[H2O] jG
R∞ ) lim R ) I0σ xf∞
jdio jGk5
(x ) mole fraction of dioxane) (16) (x ) mole fraction of dioxane) (17) CuIITSPP
The R0’s of the ν2 and ν4 modes in are shown in Figure 7. From the transient absorption kinetic data, the values of I0σjH2O/jG were estimated to be 9.1 × 109 s-1 for the ν2 mode and 1.1 × 1010 s-1 for the ν4 mode, respectively. From the R∞ and the observed k5 values, I0σjdioxane/jG is estimated to be 9.1 × 109 s-1 for the ν2 mode and 1.1 × 1010 s-1 for the ν4 mode even though the concentration of dioxane did not vary much relative to that of water. However, a weak dependence of the observed ratio in the higher dioxane concentrations allows us to accept the validity of the R∞ limiting value. From the ratio
Water-Soluble Copper(II) Porphyrins of R∞/R0, jdioxane/jH2O is found to be almost unity, indicating that the Raman scattering efficiencies for the CuIITSPP complexes with water and dioxane are nearly same. We also applied the above treatment to the results of CuII(TMpy-P4) and determined the value of I0σjdio/jG for both the ν2 and ν4 modes to be 3.9 × 109 s-1. However, because of the small value of R0 as shown in Figure 7 for CuII(TMpy-p4), we could not evaluate I0σjH2O/jG. But it is reasonable to assume that jdioxane/jH2O should not be much different from unity because the nature of the transient complex of CuII(TMpy-P4) would be similar to that of CuIITSPP. Therefore, we can assume the value of I0σjH2O/jG to be 3.9 × 109 s-1. With the experimentally determined k4, k5, I0σjH2O/jG, I0σjdioxane/ jG, and jdioxane/jH2O, we simulated the experimental data employing k2/k1 as an adjustable parameter. As shown in Figure 7, the factors of 32 and 12 for the k2/k1 values for CuIITSPP and CuII(TMpy-P4), respectively, can reproduce the experimental data with good correlation, supporting the validity of our reaction model. Furthermore, the good agreement between the value of k2/k1 obtained from the Raman spectroscopic methods and that from the time-resolved transient absorption measurements again supports our proposed mechanism for the ligand binding/ releasing processes of the transient complex of copper(II) porphyrins in the water/dioxane mixed solvent. Meanwhile, it is noteworthy that water-soluble copper(II) porphyrins have different formation and decay rate constants depending on the oxygen-containing solvent molecules. In particular, the larger the formation constant of the complex of copper(II) porphyrins and oxygen-containing solvents, the longer the lifetime of excited copper(II) porphyrins that was observed. Similar phenomena for several copper(II) porphyrins have already been observed in picosecond transient absorption measurements by Kim et al.5a They reported that the nitrogencontaining solvent molecules with larger ground state complex formation constants exhibit longer lifetimes for excited state copper(II) porphyrins. Assuming that the change of coordinating solvent molecules only perturbs the quenching state without alteration of the other electronic states of copper(II) porphyrins, the observed correlation between the formation and decay rate constants for several oxygen- and nitrogen-containing solvent molecules can be explained by the change in the activation energies of reaction steps 5 and 6. This interpretation can be applied to CuII(TMpy-P4) in water/dioxane directly, but the situation for CuIITSPP is slightly different because of the fivecoordinated complex formation with both water and dioxane in the ground state. However, it is reasonable to assume that upon complex formation of copper(II) porphyrins with solvent molecules, the changes in the potential energy surfaces for the 2S , 2S (π,π*) and 2T/4T(π,π*) states are not significant 0 1 compared to those of the quenching states.13 Although the current system has been investigated by several authors,20-24 the importance of the overall kinetics of the excited states of water-soluble copper(II) porphyrins has not been considered. In this report, however, we show that the appearance and disappearance of certain transient Raman peaks in the nanosecond TR3 spectra in water-soluble copper(II) porphyrins are dependent upon the overall decay dynamics of photoexcited copper(II) porphyrins. Further nanosecond and picosecond TR3 studies as well as the time-resolved transient absorption experiments on the complexes of CuII(TMpy-P4) with some polynucleotides are planned to derive information on their excited state complex formation and decay kinetics. Acknowledgment. This work has been supported by KOSEF through the Center for Molecular Science and MOST (S.C.J. and D.K.), by the Basic Science Research Institute Program,
J. Phys. Chem., Vol. 100, No. 8, 1996 3083 Ministry of Education (BSRI-95-3432), and by the Korea Research Institute of Standards and Science (M.Y.). References and Notes (1) Gouterman, M. In The Porphyrins; Dolphin, D., Ed.; Academic Press: New York, 1978; Vol. III, Chapter 1. (2) Kobayashi, T.; Huppert, D.; Strub, K. D.; Rentzepis, P. M. J. Chem. Phys. 1979, 70, 1720. (3) Magde, D.; Windsor, M. W.; Holten, D.; Gouterman, M. Chem. Phys. Lett. 1974, 29, 183. (4) Antipas, A.; Dolphin, D.; Gouterman, M.; Johnson, E. C. J. Am. Chem. Soc. 1978, 100, 7705. (5) (a) Kim, D.; Holten, D.; Gouterman, M. J. Am. Chem. Soc. 1984, 106, 2793. (b) Yan, X.; Holten, D. J. Phys. Chem. 1988, 92, 5982. (6) Kruglik, S. G.; Apanasevich, P. A.; Chirvony, V. S.; Kvach, V. A. J. Phys. Chem. 1995, 99, 2978. (7) de Paula, J. C.; Walters, V. A.; Jackson, B. A.; Cardozo, K. J. Phys. Chem. 1995, 99, 4373. (8) Jeoung, S. C.; Kim, D.; Cho, D. W.; Yoon, M. J. Phys. Chem. 1995, 99, 5826. (9) Apanasevich, P. A.; Ermolenkov, V. V.; Kruglik, S. G.; Kvach, V. V.; Orlovich, V. A. In Proceedings of 6th International Conference on TimeResolVed Vibrational Spectroscopy; Lau, A., Siebert, F., Werncke, W., Eds.; Springer-Verlag: Berlin, Heidelberg, 1994; Vol. 74, pp 120-123. (10) Zerner, M.; Gouterman, M. Theor. Chim. Acta 1966, 4, 44. (11) Case, D. A.; Karplus, M. J. Am. Chem. Soc. 1977, 99, 6182. (12) (a) Roos, B.; Sundborm, M. J. Mol. Spectrosc. 1970, 36, 8. (b) Henriksson, A.; Roos, B.; Sundborm, M. Theor. Chim. Acta 1972, 27, 303. (13) Stavrev, K.; Zener, M. Chem. Phys. Lett. 1995, 233, 179. (14) Paraseuth, D.; Gaudemer, A.; Verlhac, J. B.; Kraljic, I.; Sissoeff, I.; Guille, E. Photochem. Photobiol. 1986, 44, 717. (15) Akins, D. L.; Zhu, H.-R.; Guo, C. J. Phys. Chem. 1994, 98, 3612. (16) Pasternak, R. F.; Gibbs, E. J.; Villafranca, J. J. Biochemistry 1983, 22, 2406. (17) Geacintov, N. E.; Ibanez, V.; Rougee, M.; Bensasson, R. V. Biochemistry 1987, 26, 3087. (18) Dougherty, G.; Pilbrow, J. R.; Skorobogaty, A.; Smith, T. D. J. Chem. Soc., Faraday Trans. 2 1985, 81, 1739. (19) Marzilli, L. G.; Banville, D. L.; Zon, G.; Wilson, W. D. J. Am. Chem. Soc. 1986, 108, 4188. (20) Blom, N.; Odo, J.; Nanamoto, K.; Strommen, D. P. J. Phys. Chem. 1986, 90, 2847. (21) Turpin, P.-Y.; Chinsky, L.; Laigle, A.; Tsuboi, M.; Kincaid, J. R.; Nakamoto, K. Photochem. Photobiol. 1990, 51, 519. (22) Chinsky, L.; Turpin, P.-Y.; Al-Obaidi, A.; Bell, S. E. J.; Hester, R. E. J. Phys. Chem. 1991, 95, 5754. (23) Strahan, G. D.; Ln, D.; Tsuboi, M.; Nakamoto, K. J. Phys. Chem. 1992, 96, 6450. (24) Mojzes, P.; Chinsky, L.; Turpin, P.-Y. J. Phys. Chem. 1993, 97, 4841. (25) Kruglik, S. G.; Galievsky, V. A.; Chirvony, V. S.; Apanasevich, P. A.; Ermolenkov, V. V.; Orlovich, V. A.; Chinsky, L.; Turpin, P.-Y. J. Phys. Chem. 1995, 99, 5732. (26) Parthasarathi, N.; Hansen, C.; Yamaguchi, S.; Spiro, T. G. J. Am. Chem. Soc., 1987, 109, 3865. (27) Findsen, E. W.; Shelnutt, J. A.; Ondrias, M. R. J. Phys. Chem. 1988, 92, 307. (28) (a) Findsen, E. W.; Alston, K.; Shelnutt, J. A.; Ondrias, M. R. J. Am. Chem. Soc. 1986, 108, 4009. (b) Kim, D.; Holten, D. Chem. Phys. Lett. 1983, 98, 584. (c) Kim, D.; Kirmaier, C.; Holten, D. Chem. Phys. 1983, 75, 305. (d) Chikishev, A. Yu; Kamalov, V. F.; Koroteev, N. I.; Kvach, V. V.; Shkurinov, A. P.; Toleutaev, B. N. Chem. Phys. Lett. 1988, 144, 90. (e) Kim, D.; Su, Y. O.; Spiro, T. G. Inorg. Chem. 1986, 25, 3988. (f) Findsen, E. W.; Shelnutt, J. A.; Friedman, J. M.; Ondrias, M. R. Chem. Phys. Lett. 1986, 126, 465. (g) Kim, D.; Spiro, T. G. J. Am. Chem. Soc. 1986, 108, 2099. (h) Sato, A.; Kitagawa, T. In Proceedings of 6th International Conference on Time-ResolVed Vibrational Spectroscopy; Lau, A., Siebert, F., Werncke, W., Eds.; Springer-Verlag: Berlin, Heidelberg, 1994; Vol. 74, pp 104-108. (29) Tait, C. D.; Holten, D.; Gouterman, M. J. Am. Chem. Soc. 1984, 106, 6653. (30) Ake, R. L.; Gouterman, M. Theor. Chim. Acta 1970, 17, 408. (31) (a) Fajer, J. In The Porphyrins; Dolphin, D., Ed.; Academic Press: New York, 1978; Vol. IV, p 198. (b) Oertling, W. A.; Salehi, A.; Chung, Y. C.; Leroi, G. E.; Chang, C. K.; Babcock, G. T. J. Phys. Chem. 1987, 91, 5887. (c) Oertling, W. A.; Salehi, A.; Chang, C. K.; Babcock, G. T. J. Phys. Chem. 1989, 93, 1311. (d) Kim, D.; Miller, L. A.; Rakhit, G.; Spiro, T. G. J. Phys. Chem. 1986, 90, 3320. (e) Czernuszewicz, R. S.; Macor, K. A.; Li, X.-Y.; Kincaid, J. R.; Spiro, T. G. J. Am. Chem. Soc. 1989, 111, 3860.
JP951001U
