Photochemistry of Axially-Coordinated Ruthenium Phthalocyanine Complexes and Deactivation of Laser-Dye DCM

Abstract

수용성, axially coordinated ruthenium phthalocyanine complexes, K_(2)[RuPc(L)_(2)] ( L_(1) = TPPMS = triphenylphosphinemonosulfonate, L_(2) = 3-pyridinesulfonate )을 합성하여 aggregation을 배제한 phthalocyanine 착물 분자의 화학적, 광화학적 성질을 알아보았다. 이 화합물은 중성 혹은 염기성인 조건에서 안정하고 흡수스펙트럼은 phthalocyanine moiety에 의한 강한 B (315 nm) band 와 Q (650 nm) band를 보인다. B와 Q band의excitation으로 각각 약한 fluorescence emission을 나타내었다. 용매의dielectric constant에 따라 흡수스펙트럼의 최대흡광파장이 이동하는 것으로부터 각각의 band를 n→π^(*)와 π→π^(*) transition에 의한 것으로 band assign을 할수 있었다. 산성용액에서는 phthalocyanine의 peripheral N에 protonation되기 때문에 720 nm 근처에서 새로운 peak가 발견됨을 확인하였다. 축방향 리간드인 L_(1) 과 L_(2)의 차이때문에 용액중에서 K_(2)[RuPc(3-pyridinesulfonate)_(2)]는 6배위인 [RuPc(3-pyridinesulfonate)_(2)]^(2-)로 또 K_(2)[RuPc(TPPMS)_(2)]는 5배위인 [RuPc(TPPMS)]^(-)와 6배위인 [RuPc(TPPMS)_(2)]^(2-)로 존재함을 ^(31)P-NMR로 알수 있다. 나아가 이것을 다른 화합물과의 에너지전이에서 에너지 수용체로 사용할 때 matrix에 따른 에너지전이 mechanism을 알아보기 위한 에너지주개로 laser-dye DCM을 사용하였다. 에너지전이에 앞서 DCM 자체의 광화학적 성질을 확인함에 있어서 그 matrix로 siloxane polymer인 methylphenylres고(MP-Resin)을 사용하였다. MP-Resin에서 DCM은 일반 용매를 사용하였을 ??와는 다른 양상을 보였으며 특히 resin이 경화되어감에 따라 quantum yield가 증가하고 특이한 광이성질체 현상을 보였다. DCM 과 K_(2)[RuPc(L)_(2)]와의 에너지 전이는 아래 식과 같은 복사 에너지전이가 주된 경로 임을 알 수 있었고, D^(*) → D + hv hv + A → A^(*) 에너지 전이 상수 Ket 가 10^(12) 정도로 커서 효과적인 에너지전이가 일어남을 확인하였다. MP-Resin에서는 resin의 경화가 진행될수록 전이가 더욱더 잘 진행됨을 관찰하였다.;Water-soluble, mon-aggregating and axially coordinated ruthenium phthalocyanine complexes, K_(2)[RuPc(L)_(2)] (L_(1) = TPPMS = triphenylphosphinernonosulfonate, L_(2) = 3-yridinesulfonate) were preared and their chemical and photochemical properties were investigated. These complexes are stable in the neutral and basic conditions. Their absorption spectra shows strong B (315 nm) band and Q (650 nm) band by the phthalocyanine moiety. Both of B and Q band show weak fluorescence emissions. Each band can be assigned to n→π^(*) and π→π^(*) transition from the observation that the absorption peak maxima shift with changing the dielectric constant of solvents. In acidic condition, new absorption peak in formed at 720 nm as the peripheral N's of phthalocyanine are protonated. As the axial ligands of L_(1) and L_(2) are different, K_(2)[RuPc(3-pyridinesulfonate)_(2)] exists as 6-coordinated complex, [RuPc(3-pyridinesulfonate)_(2)]^(2-), in solution but K_(2)[RuPc(TPPMS)_(2)] as both 5-and 6-coordinated complexes, [RuPc(TPPMS)]^(-) and [RuPc(TPPMS)_(2)]^(2). Energy transfer between organic dye DCM and K_(2)[RuPc(L)_(2)] complexes was investigated and the mechanism was sugggested. Methylphenyl resin (MP-Resin) was used at the matrix for the study of the photochemical properties of DCM. MP-Resin, a branched or layerd siloxane polymer that has the substituted methyl and phenyl group, is plasticized in a proper vacuum and temperature condition. In MP-Resin, DCM exhibited different features in comparison with the normal solution : ⅰ)the quantum yield increased ⅱ)particular photo-isomerization occurred as MP-Resin was plasticized. The mechanism of energy transfer between DCM and K_(2)[RuPc(L)_(2)] complexes is radiative energy transfer process below, D^(*) → D + hv hv + A → A^(*) and the energy transfer constant k_(et) is about 10^(12). So highly efficient energy transfer is occurred and is more efficient as the plasticization proceeds on.