- Email: [email protected]
Synthesis and spectroscopic properties of heteroleptic sandwich-type (phthalocyaninato)(porphyrinato)lanthanide(III) complexes
Inorganica Chimica Acta 255 (1997) 59–64
Synthesis and spectroscopic properties of heteroleptic sandwich-type (phthalocyaninato)(porphyrinato)lanthanide(III) complexes Jianzhuang Jiang 1, Rebecca L.C. Lau, T.W. Dominic Chan, Thomas C.W. Mak, Dennis K.P. Ng U Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
Received 13 February 1996; revised 12 April 1996
Abstract
Treatment of dilithium phthalocyaninate [Li2(Pc)] with LnIII(acac)(TPP) (LnsSm, Eu, Gd; acacsacetylacetonate; TPPs5,10,15,20tetraphenylporphyrinate) prepared in situ from Ln(acac)3PnH2O and (TPP)H2 in 1,2,4-trichlorobenzene led to the formation of heteroleptic triple-decker complexes (TPP)LnIII(Pc)LnIII(TPP) and (Pc)LnIII(Pc)LnIII(TPP) along with a small amount of the double-deckercomplexes LnIII(Pc)(TPP). The new compounds were characterised with 1H NMR, UV–Vis, near-IR and Fourier transform ion cyclotron resonance (FTICR) mass spectrometry. Keywords:
Lanthanide(III) complexes; Phthalocyanine complexes; Porphyrin complexes; Macrocyclic ligand complexes; Sandwich complexes
1. Introduction
Sandwich-type phthalocyaninato and porphyrinato metal complexes, in which the highly delocalised macrocycles are in close proximity, have been the subject of intensive research in recent years [1]. Due to the strong electronic interactions between the p electron systems of the macrocycles, these complexes display unusual electrical [2], magnetic [3], optical [4] and electrochromic properties [5]. The doubledecker complexes MIV(Por)2 (MsCe, U, Th, Zr, Hf; Porsgeneral porphyrinate) have also been proposed as models to mimic the structure and spectroscopic properties of the ‘special pair’ found in the reaction centre of photosynthetic bacteria [6]. In order to gain a more thorough understanding of the nature of such p–p interactions, a wide range of double-decker and triple-decker metal complexes, M(P)2 and M2(P)3 (Psphthalocyaninate (Pc) or porphyrinate), have been extensively studied. Most of the known examples are symmetric and contain the same macrocyclic ligands [7]. Hole delocalisation has been observed for the homoleptic double-decker complexes [M(P)2]nq (Mstrivalent metals, ns0; Mstetravalent metals, ns1) [8] and triple-decker complexes [M2(P)3]q (Mstrivalent metals) [9]. The hetCorresponding author. On leave from the Department of Chemistry, Peking University, Beijing 100871, People’s Republic of China. U
1
eroleptic analogues, in particular, those with mixed phthalocyaninato and porphyrinato ligands are of much interest since the individual chromophores show very different optical and redox properties which can provide insight into the problem of hole localisation or delocalisation in this class of complexes [10,11]. However, heteroleptic (phthalocyaninato)(porphyrinato)metal complexes have been relatively little studied. To our knowledge, the double-decker complexes MIV(Pc)(Por) (MsZr [12], Hf [12], Ce [13], U [14], Th [14]) and LnIII(Pc)(Por) (LnsLa, Pr, Nd, Eu, Gd, Er, Lu, Y) [15–17] and the triple-decker complexes LnIII2(Pc)(Por)2 (LnsCe [18], Gd [15]) and LnIII2(Pc)2(Por) (LnsCe [18], Nd [19], Eu [19], Gd [19]) are the only examples reported so far. In this paper, the synthesis and spectroscopic properties of further examples of the rare heteroleptic triple-decker complexes, namely LnIII2(Pc)(TPP)2 and LnIII2(Pc)2(TPP) (LnsSm, Eu, Gd), are described. 2. Experimental 2.1. General
Dichloromethane (BDH, AR grade) and methanol (BDH, AR grade) were used as received. Hexanes ‘mixture’ (Shell) was distilled from anhydrous CaCl2. 1,2,4-Trichlorobenzene
0020-1693/97/$17.00 q 1997 Elsevier Science S.A. All rights reserved PII S0020-1693(96)05336-4
Journal: ICA (Inorganica Chimica Acta)
Article: 5336
60
J. Jiang et al. / Inorganica Chimica Acta 255 (1997) 59–64
(Aldrich) was dried over 4 A˚ molecular sieves and distilled under reduced pressure. The compounds Ln(acac)3PnH2O [20], (TPP)H2 [21] and Li2(Pc) [22] were prepared according to the literature methods. The 1H NMR spectra were recorded on a Bruker WM 250 spectrometer or a Bruker ARX 500 spectrometer in CDCl3 and are reported in ppm with an SiMe4 reference. The UV– Vis and near-IR absorption spectra were obtained on a Hitachi U-3300 and a Hitachi U-3100 spectrophotometer, respectively. Fast atom bombardment (FAB) mass spectra were measured on a Bruker APEX 47e ultra-high resolution Fourier transform ion cyclotron resonance (FTICR) mass spectrometer with 3-nitrobenzyl alcohol as matrix. Elemental analyses were performed by the Department of Chemistry, National Taiwan University. 2.2. General procedure for the preparation of Ln2(Pc)(TPP)2, Ln2(Pc)2(TPP) and Ln(Pc)(TPP)
A mixture of (TPP)H2 (62 mg, 0.10 mmol) and Ln(acac)3PnH2O (LnsSm, Eu, Gd) (150 mg, ;0.3 mmol) in 1,2,4-trichlorobenzene (20 ml) was refluxed for 4 h under a slow stream of nitrogen. The resulting dark cherry-red solution was cooled to room temperature before adding Li2(Pc) (80 mg, 0.15 mmol). The mixture was refluxed for a further 3 h, then the solvent was removed under vacuum. The residue was chromatographed on a silica gel column (Merck, 70– 230 mesh) with CH2Cl2 as eluent to give an olive-brown band which contained mainly the triple-decker complexes Ln2(Pc)(TPP)2 and a small amount of unreacted (TPP)H2. The column was further eluted with CH2Cl2/CH3OH (10:1) to give a dark greenish blue band which contained the tripledecker complexes Ln2(Pc)2(TPP) and a trace amount of the double-decker complexes Ln(Pc)(TPP). The first fraction was concentrated and chromatographed again with CH2Cl2/ hexanes (1:1) as eluent to remove the (TPP)H2. The solution containing the triple-deckers Ln2(Pc)(TPP)2 was evaporated to give a violet–blue solid which was recrystallisedfrom a CH2Cl2/CH3OH mixture. Similarly, the second fraction was concentrated and loaded onto a silica gel column. The eluent CH2Cl2/CH3OH (20:1) was used initially to develop a yellowish-brown band which contained Ln(Pc)(TPP) (;2–5 mg). Then the column was further eluted with CH2Cl2/CH3OH (10:1) to give a blue band containing Ln2(Pc)2(TPP). The crude product was purified by chromatography again under similar conditions followed by recrystallisation from a mixture of CH2Cl2/CH3OH. 2.2.1. Preparation of Sm2(Pc)(TPP)2 (1a), Sm2(Pc)2(TPP) (2a) and Sm(Pc)(TPP) (3a) By using the general procedure with Sm(acac)3PnH2O as starting material, Sm2(Pc)(TPP)2 (1a) (69 mg, 68%), Sm2(Pc)2(TPP) (2a) (23 mg, 16%) and a trace amount of Sm(Pc)(TPP) (3a) were obtained. 1a. 1H NMR (500 MHz): d 8.25 (br s, 8H, Pc), 7.75 (br
s, 8H, Pc), 7.58 (br s, 16H, Ph), 7.45 (br s, 8H, Ph), 7.09
(t, Js7.4 Hz, 8H, Ph), 6.70 (d, Js7.2 Hz, 8H, Ph), 6.67 (s, 16H, pyrH). 2a. 1H NMR (500 MHz): d 8.09 (br s, 4H, Ph), 7.95 (br s, 8H, Pc), 7.80 (br s, 8H, Pc), 7.72 (br s, 16H, Pc), 7.63 (br s, 4H, Ph), 7.47 (br s, 4H, Ph), 7.13 (br s, 4H, Ph), 6.86 (br s, 4H, Ph), 6.60 (br s, 8H, pyrH). 2.2.2. Preparation of Eu2(Pc)(TPP)2 (1b), Eu2(Pc)2(TPP) (2b) and Eu(Pc)(TPP) (3b)
By employing the general procedure described above with Eu(acac)3PnH2O as starting material, Eu2(Pc)(TPP)2 (1b) (63 mg, 62%), Eu2(Pc)2(TPP) (2b) (22 mg, 15%) and a trace amount of Eu(Pc)(TPP) (3b) were obtained. 1b. 1H NMR (250 MHz): d 12.87 (br s, 8H, Pc), 11.90 (br s, 8H, Ph), 10.72 (br s, 8H, Pc), 9.14 (t, Js7.0 Hz, 8H, Ph), 8.11 (t, Js7.5 Hz, 8H, Ph), 6.75 (t, Js7.3 Hz, 8H, Ph), 4.81 (d, Js7.0 Hz, 8H, Ph), 3.93 (br s, 16H, pyrH). Anal. Calc. for C120H72N16Eu2: C, 70.59; H, 3.55; N, 10.98. Found: C, 69.88; H, 3.76; N, 10.36%. 2b. 1H NMR (250 MHz): d 13.04 (br s, 8H, Pc), 12.38 (br s, 4H, Ph), 11.13 (br s, 8H, Pc), 10.17 (br s, 8H, Pc), 9.32 (br s, 4H, Ph), 8.78 (br s, 8H, Pc), 8.18 (br s, 4H, Ph), 6.78 (br s, 4H, Ph), 4.94 (br s, 4H, Ph), 3.21 (br s, 8H, pyrH).
2.2.3. Preparation of Gd2(Pc)(TPP)2 (1c), Gd2(Pc)2(TPP) (2c) and Gd(Pc)(TPP) (3c) Compound Gd(acac)3PnH2O (300 mg, 0.6 mmol) was
treated with (TPP)H2 (124 mg, 0.20 mmol) and Li2(Pc) (210 mg, 0.39 mmol) to produce Gd2(Pc)(TPP)2 (1c) (138 mg, 67%), Gd2(Pc)2(TPP) (2c) (65 mg, 17%) and a trace amount of Gd(Pc)(TPP) (3c) according to the general procedure. 3. Results and discussion
The porphyrin (TPP)H2 was treated with 3 equiv. of Ln(acac)3PnH2O (LnsSm, Eu, Gd) in refluxing 1,2,4trichlorobenzene. The progress of the reactions was monitored by UV–Vis spectrometry and the conversions were essentially completed in ;4 h. The UV–Vis spectra of the resulting Ln(acac)(TPP) were virtually identical to those reported previously [23]. The mixtures were then treated with 1.5 equiv. of Li2(Pc) for a further 3 h to give mixtures of Ln2(Pc)(TPP)2 (1a–c) (62–68%), Ln2(Pc)2(TPP) (2a–c) (15–17%) and Ln(Pc)(TPP) (3a–c) (trace amounts), which could be separated by chromatography (Scheme 1). The triple-decker complexes were further purified by recrystallisation from a mixture of CH2Cl2 and CH3OH. It is worth noting that for similar reactions using 5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin[(TMPP)H2] instead of (TPP)H2, only the triple-decker complexes Ln2(Pc)2(TMPP) (LnsNd, Eu, Gd) were isolated [19]. The reactions described here are also different from those involving the late lanthanide metal salts. Treatment of
Journal: ICA (Inorganica Chimica Acta)
Article: 5336
J. Jiang et al. / Inorganica Chimica Acta 255 (1997) 59–64
61
Scheme 1.
Fig. 1. 1H NMR spectra of (a) Eu2(Pc)(TPP)2 (1b) and (b) Eu2(Pc)2(TPP) (2b) in CDCl3. ) indicates residual CHCl3.
Journal: ICA (Inorganica Chimica Acta)
Article: 5336
62
J. Jiang et al. / Inorganica Chimica Acta 255 (1997) 59–64
Fig. 2. UV–Vis spectra of Sm2(Pc)(TPP)2 (1a) (- - -) and Sm2(Pc)2(TPP) (2a) (——) in CH2Cl2.
Ln(acac)3PnH2O (LnsEr, Lu, Y) with (TPP)H2 in a similar manner led to the formation of double-decker complexes Ln(Pc)(TPP) as the sole product [16]. The reactions, however, are in accord with the results reported for the cerium analogue [18]. Mixtures of CeIV(Pc9)(Por), CeIII2(Pc9)(Por)2 and CeIII2(Pc9)2(Por) (Pc9sPc, 2,3,9,10,16,17,
23,24-octamethoxyphthalocyaninate; PorsTPP, TMPP) were obtained by similar treatments on Ce(acac)3PnH2O. However, as mentioned below, the structures of 2a–c and Ce2(Pc)2(Por) are clearly different. These experiments indicate that the yields, distribution and structures of the doubledecker and triple-decker complexes may depend on the nature of the lanthanide metals and the macrocycles used in the reactions. The 1H NMR spectra of the triple-decker complexes Ln2(Pc)(TPP)2 and Ln2(Pc)2(TPP) (LnsSm, Eu) were recorded giving valuable structural information. Due to the strong paramagnetic property of the GdIII ion, the spectra of the analogous gadolinium compounds could not be obtained. NMR data for these heteroleptic triple-decker complexes are scarce and have only been reported for the cerium complexes [18]. Fig. 1(a) shows the 1H NMR spectrum of Eu2(Pc)(TPP)2 (1b) in CDCl3. The broad signals at d 12.87 and 10.72 can be assigned to the a and b protons of the phthalocyanine, respectively. The partially resolved signals at d 11.90, 9.14, 8.11, 6.75 and 4.81 are attributed to the phenyl protons. The presence of five distinct signals for the phenyl groups clearly indicates that there is a restricted rota-
Fig. 3. Observed (bottom) and simulated (top) isotopic distribution for the molecular ions (a) [Eu(Pc)(TPP)]q (3bq), (b) [Eu2(Pc)2(TPP)]q (2bq) and (c) [Gd2(Pc)(TPP)2]q (1cq) in the corresponding FAB-FTICR mass spectra.
Journal: ICA (Inorganica Chimica Acta)
Article: 5336
63
J. Jiang et al. / Inorganica Chimica Acta 255 (1997) 59–64
Table 1 The UV–Vis and near-IR data for the double-decker and triple-decker complexes in CH2Cl2 Compound
lmax (nm) (log e)
Sm2(Pc)(TPP)2 (1a) Eu2(Pc)(TPP)2 (1b) Gd2(Pc)(TPP)2 (1c) Sm2(Pc)2(TPP) (2a) Eu2(Pc)2(TPP) (2b) Gd2(Pc)2(TPP) (2c) Sm(Pc)(TPP) (3a) Eu(Pc)(TPP) (3b) Gd(Pc)(TPP) (3c)
355 (5.02), 418 (5.29), 487 (4.51), 546 (4.09), 605 (4.31) 354 (5.09), 417 (5.35), 488 (4.56), 539 (4.10), 605 (4.33) 353 (5.08), 417 (5.36), 491 (4.61), 556 (4.14), 604 (4.36) 340 (5.16), 414 (4.94), 521 (4.40), 555 (4.33), 617 (4.79), 719 (4.52) 341 (5.18), 411 (4.97), 518 (4.42), 554 (4.33), 616 (4.80), 722 (4.49) 340 (5.16), 411 (4.92), 520 (4.38), 558 (4.29), 617 (4.80), 728 (4.46) 324 (4.76), 406 (4.89), 473 (4.48), 996 (3.37), 1384 (3.60) 319 (4.79), 403 (4.87), 473 (4.47), 1011 (3.35), 1375 (3.53) 316 (4.81), 402 (4.88), 473 (4.50), 1020 (3.31), 1350 (3.54)
tion about the C(meso)–C(phenyl) bond. The remaining singlet at d 3.93 is ascribed to the porphyrin b-pyrrole protons. These results along with the integration are consistent with the triple-decker structure (TPP)Eu(Pc)Eu(TPP) in which two paramagnetic metal centres aresandwichedamong two outer porphyrin and one inner phthalocyanine macrocycles. The 1H NMR spectrum of Eu2(Pc)2(TPP) (2b) is given in Fig. 1(b). The four broad resonances at d 13.04, 11.13, 10.17 and 8.78 having roughly the same intensity may be due to the a and b protons of two inequivalent phthalocyanines. The broad bands at d 12.38, 9.32, 8.18, 6.78 and 4.94 are assigned to the five phenyl protons, while the signal at d 3.21 is ascribed to the pyrrole protons in TPP. The integration shows that there are two Pc moieties and one TPP moiety in the molecule. These NMR data suggest that 2b has theunsymmetrical structure (TPP)Eu(Pc)Eu(Pc). This arrangement of macrocycles is in accord with the structure reported for Ln2(Pc)2(TMPP) (LnsNd, Eu, Gd) [19], but differs from that of the cerium analogues in which the arrangement (Pc)Ce(Por)Ce(Pc) was revealed by X-ray studies [18]. The samarium compounds 1a and 2a also gave 1H NMR spectra which were consistent with the structures (TPP)Sm(Pc)Sm(TPP) and (TPP)Sm(Pc)Sm(Pc), respectively. However, the resonances appeared in a much narrower range (d 6.6–8.3) than those arising from the europium analogues indicating a decrease in paramagnetic shift in the samarium compounds. The electronic absorption spectra of the double-decker complexes Ln(Pc)(TPP) (3a–c) and the triple-decker complexes Ln2(Pc)(TPP)2 (1a–c) and Ln2(Pc)2(TPP) (2a–c) were measured and the data are summarised in Table 1. The UV–Vis and near-IR spectra of compounds 3a–c were very similar to those reported previously and could be assigned in the same way [15,16]. Consistent with the literature results, the lower-energy near-IR band which was attributed to an intramolecular ring-to-ring charge transfer transition was blue-shifted when the ionic radius of the central metal ion decreased from samarium to gadolinium. Fig. 2 shows typical UV–Vis spectra of the samariumcomplexes 1a and 2a, which are closely related to the spectra reported for Ln2(Pc)(TPP)2 (LnsCe, Gd) [15,18] and
Ln2(Pc)2(TMPP) (LnsNd, Eu, Gd) [19], respectively. The absorptions at 340–355 and 411–418 nm can be attributed to the phthalocyanine and porphyrin Soret bands, respectively. The remaining absorptions in the visible region may be due to the Q bands of phthalocyanine and porphyrin in which the lower-energy Q bands are contributed mainly by phthalocyanine. It is noteworthy that the porphyrin Soret band has higher intensity than the phthalocyanine Soret band in 1a, but the order is reversed in 2a as the Pc to TPP ratio increases from 1/2 to 2. The high resolution FAB mass spectra of the compounds 1a–c, 2a–c and 3b were measured using an FTICR mass spectrometer. The molecular ions were detected in all cases. Fig. 3(a) shows the molecular ion region in the spectrum of Eu(Pc)(TPP) (3b) in which distinct isotopic distribution can be observed. The relative abundance of the isotopic peaks is slightly deviated from the simulated spectrum of [Eu(Pc)(TPP)]q as shown in the top-insert. Presumably, a substantial amount of the protonated species [EuH(Pc)(TPP)]q with an isotopic envelope shifted by one mass unit is also present which distorts the isotopic pattern. The co-existence of monocation and protonated species may also occur in the triple-decker complexes. For example, the corresponding isotopic envelope in the spectrum of Eu2(Pc)2(TPP) (2b) is given in Fig. 3(b) (bottom), which Table 2 The FAB-FTICR mass spectral data for the double-decker and triple-decker complexes Compound
Calculated value a (m/z)
Measured value a (m/z)
Error (Dalton)
Sm2(Pc)(TPP)2 (1a) Eu2(Pc)(TPP)2 (1b) Gd2(Pc)(TPP)2 (1c) Sm2(Pc)2(TPP) (2a) Eu2(Pc)2(TPP) (2b) Gd2(Pc)2(TPP) (2c) Eu(Pc)(TPP) (3b)
2038.44 2041.45 2052.46 1938.36 1941.37 1952.39 1277.31
2038.91 2041.63 2052.92 1938.72 1941.70 1952.65 1277.52
0.47 0.18 0.46 0.36 0.33 0.26 0.21
Mass corresponding to the most abundant isotopic peak of the molecular ion.
a
Journal: ICA (Inorganica Chimica Acta)
Article: 5336
64
J. Jiang et al. / Inorganica Chimica Acta 255 (1997) 59–64
also shows a slight deviation from the expected pattern for [Eu2(Pc)2(TPP)]q (top). However, for the samarium and gadolinium triple-decker complexes, it is difficult to determine whether a protonated species is also present as the number of isotopes increases from Eu to Gd and Sm. This is exemplified by Fig. 3(c) showing the pattern arising from Gd2(Pc)(TPP)2 (1c). The mass spectral resultsaretabulated in Table 2. Acknowledgements
Financial support from the Hong Kong Research Grants Council (RGC Earmarked Grant CUHK 311/94P) and The Chinese University of Hong Kong (Incentive Fund 94/95) is gratefully acknowledged. We also thank Professor TienYau Luh for performing the microanalysis and the RGC for providing the funds for the purchase of the Bruker ARX 500 spectrometer through the RGC Central Allocation Scheme 1992. References
[1] K. Kasuga and M. Tsutsui, Coord. Chem. Rev., 32 (1980) 67; M. Hanack, S. Deger and A. Lange, Coord. Chem. Rev., 83 (1988) 115; M. Hanack and M. Lang, Adv. Mater., 6 (1994) 819. [2] J.-J. Andre´, K. Holczer, P. Petit, M.-T. Riou, C. Clarisse, R. Even, M. Fourmigue and J. Simon, Chem. Phys. Lett., 115 (1985) 463; P. Turek, P. Petit, J.-J. Andre´, J. Simon, R. Even, B. Boudjema, G. Guillaud and M. Maitrot, J. Am. Chem. Soc., 109 (1987) 5119; M. Maitrot, G. Guillaud, B. Boudjema, J.-J. Andre´, H. Strzelecka, J. Simon and R. Even, Chem. Phys. Lett., 133 (1987) 59; J. Padilla and W.E. Hatfield, Synth. Met., 29 (1989) F45; M. Bouvet and J. Simon, Chem. Phys. Lett., 172 (1990) 299; K.R. Rickwood, D.R. Lovett, B. Lukas and J. Silver, J. Mater. Chem., 5 (1995) 725. [3] K.L. Trojan, W.E. Hatfield, K.D. Kepler and M.L. Kirk, J. Appl. Phys., 69 (1991) 6007; J.L. Paillaud, M. Drillon, A. De Cian, J. Fischer, R. Weiss and G. Villeneuve, Phys. Rev. Lett., 67 (1991) 244; K.L. Trojan, J.L. Kendall, K.D. Kepler and W.E. Hatfield, Inorg. Chim. Acta, 198– 200 (1992) 795; P. Petit, Synth. Met., 46 (1992) 147. [4] X. Yan and D. Holten, J. Phys. Chem., 92 (1988) 409; O. Bilsel, J. Rodriguez and D. Holten, J. Phys. Chem., 94 (1990) 3508; O. Bilsel, J. Rodriguez, D. Holten, G.S. Girolami, S.N. Milam and K.S. Suslick, J. Am. Chem. Soc., 112 (1990) 4075; O. Bilsel, J. Rodriguez, S.N. Milam, P.A. Gorlin, G.S. Girolami, K.S. Suslick and D. Holten, J. Am. Chem. Soc., 114 (1992) 6528. [5] M.M. Nicholson, in C.C. Leznoff and A.B.P. Lever (eds.), Phthalocyanines: Properties and Applications, Vol. 3, VCH, New York, 1993, pp. 71–117. [6] J.W. Buchler, K. Elsa¨sser, M. Kihn-Botulinski and B. Scharbert, Angew. Chem., Int. Ed. Engl., 25 (1986) 286; J.W. Buchler, Comments Inorg. Chem., 6 (1987) 175; G.S. Girolami, S.N. Milam and K.S. Suslick, J. Am. Chem. Soc., 110 (1988) 2011; J.W. Buchler and B. Scharbert, J. Am. Chem. Soc., 110 (1988) 4272; J.W. Buchler, M. Eberle, P. Hammerschmitt, J. Hu¨ttermann and R. Kappl, Chem. Ber.,
126 (1993) 2619; J.W. Buchler and M. Nawra, Inorg. Chem., 33 (1994) 2830. [7] J.W. Buchler and M. Knoff, in G. Blauer and H. Sund (eds.), Optical Properties and Structure of Tetrapyrroles, Walter de Gruyter, Berlin, 1985, pp. 91–105; J.W. Buchler, A. De Cian, J. Fischer, M. KihnBotulinski, H. Paulus and R. Weiss, J. Am. Chem. Soc., 108 (1986) 3652; J.W. Buchler, J. Hu¨ttermann and J. Lo¨ffler, Bull. Chem. Soc. Jpn., 61 (1988) 71; J.W. Buchler, A. De Cian, J. Fischer, M. KihnBotulinski and R. Weiss, Inorg. Chem., 27 (1988) 339; K. Kim, W.S. Lee, H.-J. Kim, S.-H. Cho, G.S. Girolami, P.A. Gorlin and K.S.Suslick, Inorg. Chem., 30 (1991) 2652; J.W. Buchler, A. De Cian, J. Fischer, P. Hammerschmitt and R. Weiss, Chem. Ber., 124 (1991) 1051; J.W. Buchler, V. Eiermann, H. Hanssum, G. Heinz, H. Ru¨terjans and M. Schwarzkopf, Chem. Ber., 127 (1994) 589; J. Jiang, R.C.W. Liu, T.C.W. Mak, T.W.D. Chan and D.K.P. Ng, Polyhedron, in press, and Refs. therein. [8] R.J. Donohoe, J.K. Duchowski and D.F. Bocian, J. Am. Chem. Soc., 110 (1988) 6119; J.K. Duchowski and D.F. Bocian, J. Am. Chem. Soc., 112 (1990) 3312; J.-H. Perng, J.K. Duchowski and D.F. Bocian, J. Phys. Chem., 94 (1990) 6684; J.-H. Perng, J.K. Duchowski and D.F. Bocian, J. Phys. Chem., 95 (1991) 1319; P.C. Martin, J. Arnold and D.F. Bocian, J. Phys. Chem., 97 (1993) 1332. [9] J.K. Duchowski and D.F. Bocian, J. Am. Chem. Soc., 112 (1990) 8807. [10] For dissimilar phthalocyaninato complexes: Y. Liu, K. Shigehara, M. Hara and A. Yamada, J. Am. Chem. Soc., 113 (1991) 440; A. Pondaven, Y. Cozien and M. L’Her, New J. Chem., 15 (1991) 515; 16 (1992) 711; F. Guyon, A. Pondaven, P. Guenot and M. L’Her, Inorg. Chem., 33 (1994) 4787. [11] For dissimilar porphyrinato complexes: J.W. Buchler, A. De Cian, J. Fischer, P. Hammerschmitt, J. Lo¨ffler, B. Scharbert and R. Weiss, Chem. Ber., 122 (1989) 2219; J.W. Buchler and J. Lo¨ffler, Z. Naturforsch., Teil B, 45 (1990) 531; J.K. Duchowski and D.F. Bocian, Inorg. Chem., 29 (1990) 4158; J.W. Buchler, M. Kihn-Botulinski, J. Lo¨ffler and B. Scharbert, New J. Chem., 16 (1992) 545; G.S. Girolami, P.A. Gorlin, S.N. Milam, K.S. Suslick and S.R. Wilson, J. Coord. Chem., 32 (1994) 173; G.S. Girolami, P.A. Gorlin and K.S. Suslick, Inorg. Chem., 33 (1994) 626; G.A. Spyroulias, A.G. Coutsolelos, C.P. Raptopoulou and A. Terzis, Inorg. Chem., 34 (1995) 2476; G.A. Spyroulias and A.G. Coutsolelos, Inorg. Chem., 35 (1996) 1382. [12] R. Guilard, J.-M. Barbe, A. Ibnlfassi, A. Zrineh, V.A. Adamian and K.M. Kadish, Inorg. Chem., 34 (1995) 1472. [13] M. Lachkar, A. De Cian, J. Fischer and R. Weiss, New J. Chem., 12 (1988) 729; T.-H. Tran-Thi, T. Fournier, A. De Cian, D. Chabach, R. Weiss, D. Houde, C. Pe´pin and L. Dao, Chem. Phys. Lett., 213 (1993) 139. [14] K.M. Kadish, G. Moninot, Y. Hu, D. Dubois, A. Ibnlfassi, J.-M. Barbe and R. Guilard, J. Am. Chem. Soc., 115 (1993) 8153. [15] T.-H. Tran-Thi, T.A. Mattioli, D. Chabach, A. De Cian and R. Weiss, J. Phys. Chem., 98 (1994) 8279. [16] D. Chabach, M. Tahiri, A. De Cian, J. Fischer, R. Weiss and M. El Malouli Bibout, J. Am. Chem. Soc., 117 (1995) 8548. [17] J. Jiang, T.C.W. Mak and D.K.P. Ng, Chem. Ber., 129 (1996) 933. [18] D. Chabach, M. Lachkar, A. De Cian, J. Fischer and R. Weiss, New J. Chem., 16 (1992) 431. [19] M. Moussavi, A. De Cian, J. Fischer and R. Weiss, Inorg. Chem., 25 (1986) 2107. [20] J.G. Stites, C.N. McCarty and L.L. Quill, J. Am. Chem. Soc., 70 (1948) 3142. [21] G.H. Barnett, M.F. Hudson and K.M. Smith, J. Chem. Soc., Perkin Trans. I, (1975) 1401. [22] P.A. Barrett, D.A. Frye and R.P. Linstead, J. Chem. Soc., (1938) 1157. [23] C.-P. Wong, Inorg. Synth., 22 (1983) 156.
Journal: ICA (Inorganica Chimica Acta)
Article: 5336
Synthesis and spectroscopic properties of heteroleptic sandwich-type (phthalocyaninato)(porphyrinato)lanthanide(III) complexes Jianzhuang Jiang 1, Rebecca L.C. Lau, T.W. Dominic Chan, Thomas C.W. Mak, Dennis K.P. Ng U Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong
Received 13 February 1996; revised 12 April 1996
Abstract
Treatment of dilithium phthalocyaninate [Li2(Pc)] with LnIII(acac)(TPP) (LnsSm, Eu, Gd; acacsacetylacetonate; TPPs5,10,15,20tetraphenylporphyrinate) prepared in situ from Ln(acac)3PnH2O and (TPP)H2 in 1,2,4-trichlorobenzene led to the formation of heteroleptic triple-decker complexes (TPP)LnIII(Pc)LnIII(TPP) and (Pc)LnIII(Pc)LnIII(TPP) along with a small amount of the double-deckercomplexes LnIII(Pc)(TPP). The new compounds were characterised with 1H NMR, UV–Vis, near-IR and Fourier transform ion cyclotron resonance (FTICR) mass spectrometry. Keywords:
Lanthanide(III) complexes; Phthalocyanine complexes; Porphyrin complexes; Macrocyclic ligand complexes; Sandwich complexes
1. Introduction
Sandwich-type phthalocyaninato and porphyrinato metal complexes, in which the highly delocalised macrocycles are in close proximity, have been the subject of intensive research in recent years [1]. Due to the strong electronic interactions between the p electron systems of the macrocycles, these complexes display unusual electrical [2], magnetic [3], optical [4] and electrochromic properties [5]. The doubledecker complexes MIV(Por)2 (MsCe, U, Th, Zr, Hf; Porsgeneral porphyrinate) have also been proposed as models to mimic the structure and spectroscopic properties of the ‘special pair’ found in the reaction centre of photosynthetic bacteria [6]. In order to gain a more thorough understanding of the nature of such p–p interactions, a wide range of double-decker and triple-decker metal complexes, M(P)2 and M2(P)3 (Psphthalocyaninate (Pc) or porphyrinate), have been extensively studied. Most of the known examples are symmetric and contain the same macrocyclic ligands [7]. Hole delocalisation has been observed for the homoleptic double-decker complexes [M(P)2]nq (Mstrivalent metals, ns0; Mstetravalent metals, ns1) [8] and triple-decker complexes [M2(P)3]q (Mstrivalent metals) [9]. The hetCorresponding author. On leave from the Department of Chemistry, Peking University, Beijing 100871, People’s Republic of China. U
1
eroleptic analogues, in particular, those with mixed phthalocyaninato and porphyrinato ligands are of much interest since the individual chromophores show very different optical and redox properties which can provide insight into the problem of hole localisation or delocalisation in this class of complexes [10,11]. However, heteroleptic (phthalocyaninato)(porphyrinato)metal complexes have been relatively little studied. To our knowledge, the double-decker complexes MIV(Pc)(Por) (MsZr [12], Hf [12], Ce [13], U [14], Th [14]) and LnIII(Pc)(Por) (LnsLa, Pr, Nd, Eu, Gd, Er, Lu, Y) [15–17] and the triple-decker complexes LnIII2(Pc)(Por)2 (LnsCe [18], Gd [15]) and LnIII2(Pc)2(Por) (LnsCe [18], Nd [19], Eu [19], Gd [19]) are the only examples reported so far. In this paper, the synthesis and spectroscopic properties of further examples of the rare heteroleptic triple-decker complexes, namely LnIII2(Pc)(TPP)2 and LnIII2(Pc)2(TPP) (LnsSm, Eu, Gd), are described. 2. Experimental 2.1. General
Dichloromethane (BDH, AR grade) and methanol (BDH, AR grade) were used as received. Hexanes ‘mixture’ (Shell) was distilled from anhydrous CaCl2. 1,2,4-Trichlorobenzene
0020-1693/97/$17.00 q 1997 Elsevier Science S.A. All rights reserved PII S0020-1693(96)05336-4
Journal: ICA (Inorganica Chimica Acta)
Article: 5336
60
J. Jiang et al. / Inorganica Chimica Acta 255 (1997) 59–64
(Aldrich) was dried over 4 A˚ molecular sieves and distilled under reduced pressure. The compounds Ln(acac)3PnH2O [20], (TPP)H2 [21] and Li2(Pc) [22] were prepared according to the literature methods. The 1H NMR spectra were recorded on a Bruker WM 250 spectrometer or a Bruker ARX 500 spectrometer in CDCl3 and are reported in ppm with an SiMe4 reference. The UV– Vis and near-IR absorption spectra were obtained on a Hitachi U-3300 and a Hitachi U-3100 spectrophotometer, respectively. Fast atom bombardment (FAB) mass spectra were measured on a Bruker APEX 47e ultra-high resolution Fourier transform ion cyclotron resonance (FTICR) mass spectrometer with 3-nitrobenzyl alcohol as matrix. Elemental analyses were performed by the Department of Chemistry, National Taiwan University. 2.2. General procedure for the preparation of Ln2(Pc)(TPP)2, Ln2(Pc)2(TPP) and Ln(Pc)(TPP)
A mixture of (TPP)H2 (62 mg, 0.10 mmol) and Ln(acac)3PnH2O (LnsSm, Eu, Gd) (150 mg, ;0.3 mmol) in 1,2,4-trichlorobenzene (20 ml) was refluxed for 4 h under a slow stream of nitrogen. The resulting dark cherry-red solution was cooled to room temperature before adding Li2(Pc) (80 mg, 0.15 mmol). The mixture was refluxed for a further 3 h, then the solvent was removed under vacuum. The residue was chromatographed on a silica gel column (Merck, 70– 230 mesh) with CH2Cl2 as eluent to give an olive-brown band which contained mainly the triple-decker complexes Ln2(Pc)(TPP)2 and a small amount of unreacted (TPP)H2. The column was further eluted with CH2Cl2/CH3OH (10:1) to give a dark greenish blue band which contained the tripledecker complexes Ln2(Pc)2(TPP) and a trace amount of the double-decker complexes Ln(Pc)(TPP). The first fraction was concentrated and chromatographed again with CH2Cl2/ hexanes (1:1) as eluent to remove the (TPP)H2. The solution containing the triple-deckers Ln2(Pc)(TPP)2 was evaporated to give a violet–blue solid which was recrystallisedfrom a CH2Cl2/CH3OH mixture. Similarly, the second fraction was concentrated and loaded onto a silica gel column. The eluent CH2Cl2/CH3OH (20:1) was used initially to develop a yellowish-brown band which contained Ln(Pc)(TPP) (;2–5 mg). Then the column was further eluted with CH2Cl2/CH3OH (10:1) to give a blue band containing Ln2(Pc)2(TPP). The crude product was purified by chromatography again under similar conditions followed by recrystallisation from a mixture of CH2Cl2/CH3OH. 2.2.1. Preparation of Sm2(Pc)(TPP)2 (1a), Sm2(Pc)2(TPP) (2a) and Sm(Pc)(TPP) (3a) By using the general procedure with Sm(acac)3PnH2O as starting material, Sm2(Pc)(TPP)2 (1a) (69 mg, 68%), Sm2(Pc)2(TPP) (2a) (23 mg, 16%) and a trace amount of Sm(Pc)(TPP) (3a) were obtained. 1a. 1H NMR (500 MHz): d 8.25 (br s, 8H, Pc), 7.75 (br
s, 8H, Pc), 7.58 (br s, 16H, Ph), 7.45 (br s, 8H, Ph), 7.09
(t, Js7.4 Hz, 8H, Ph), 6.70 (d, Js7.2 Hz, 8H, Ph), 6.67 (s, 16H, pyrH). 2a. 1H NMR (500 MHz): d 8.09 (br s, 4H, Ph), 7.95 (br s, 8H, Pc), 7.80 (br s, 8H, Pc), 7.72 (br s, 16H, Pc), 7.63 (br s, 4H, Ph), 7.47 (br s, 4H, Ph), 7.13 (br s, 4H, Ph), 6.86 (br s, 4H, Ph), 6.60 (br s, 8H, pyrH). 2.2.2. Preparation of Eu2(Pc)(TPP)2 (1b), Eu2(Pc)2(TPP) (2b) and Eu(Pc)(TPP) (3b)
By employing the general procedure described above with Eu(acac)3PnH2O as starting material, Eu2(Pc)(TPP)2 (1b) (63 mg, 62%), Eu2(Pc)2(TPP) (2b) (22 mg, 15%) and a trace amount of Eu(Pc)(TPP) (3b) were obtained. 1b. 1H NMR (250 MHz): d 12.87 (br s, 8H, Pc), 11.90 (br s, 8H, Ph), 10.72 (br s, 8H, Pc), 9.14 (t, Js7.0 Hz, 8H, Ph), 8.11 (t, Js7.5 Hz, 8H, Ph), 6.75 (t, Js7.3 Hz, 8H, Ph), 4.81 (d, Js7.0 Hz, 8H, Ph), 3.93 (br s, 16H, pyrH). Anal. Calc. for C120H72N16Eu2: C, 70.59; H, 3.55; N, 10.98. Found: C, 69.88; H, 3.76; N, 10.36%. 2b. 1H NMR (250 MHz): d 13.04 (br s, 8H, Pc), 12.38 (br s, 4H, Ph), 11.13 (br s, 8H, Pc), 10.17 (br s, 8H, Pc), 9.32 (br s, 4H, Ph), 8.78 (br s, 8H, Pc), 8.18 (br s, 4H, Ph), 6.78 (br s, 4H, Ph), 4.94 (br s, 4H, Ph), 3.21 (br s, 8H, pyrH).
2.2.3. Preparation of Gd2(Pc)(TPP)2 (1c), Gd2(Pc)2(TPP) (2c) and Gd(Pc)(TPP) (3c) Compound Gd(acac)3PnH2O (300 mg, 0.6 mmol) was
treated with (TPP)H2 (124 mg, 0.20 mmol) and Li2(Pc) (210 mg, 0.39 mmol) to produce Gd2(Pc)(TPP)2 (1c) (138 mg, 67%), Gd2(Pc)2(TPP) (2c) (65 mg, 17%) and a trace amount of Gd(Pc)(TPP) (3c) according to the general procedure. 3. Results and discussion
The porphyrin (TPP)H2 was treated with 3 equiv. of Ln(acac)3PnH2O (LnsSm, Eu, Gd) in refluxing 1,2,4trichlorobenzene. The progress of the reactions was monitored by UV–Vis spectrometry and the conversions were essentially completed in ;4 h. The UV–Vis spectra of the resulting Ln(acac)(TPP) were virtually identical to those reported previously [23]. The mixtures were then treated with 1.5 equiv. of Li2(Pc) for a further 3 h to give mixtures of Ln2(Pc)(TPP)2 (1a–c) (62–68%), Ln2(Pc)2(TPP) (2a–c) (15–17%) and Ln(Pc)(TPP) (3a–c) (trace amounts), which could be separated by chromatography (Scheme 1). The triple-decker complexes were further purified by recrystallisation from a mixture of CH2Cl2 and CH3OH. It is worth noting that for similar reactions using 5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin[(TMPP)H2] instead of (TPP)H2, only the triple-decker complexes Ln2(Pc)2(TMPP) (LnsNd, Eu, Gd) were isolated [19]. The reactions described here are also different from those involving the late lanthanide metal salts. Treatment of
Journal: ICA (Inorganica Chimica Acta)
Article: 5336
J. Jiang et al. / Inorganica Chimica Acta 255 (1997) 59–64
61
Scheme 1.
Fig. 1. 1H NMR spectra of (a) Eu2(Pc)(TPP)2 (1b) and (b) Eu2(Pc)2(TPP) (2b) in CDCl3. ) indicates residual CHCl3.
Journal: ICA (Inorganica Chimica Acta)
Article: 5336
62
J. Jiang et al. / Inorganica Chimica Acta 255 (1997) 59–64
Fig. 2. UV–Vis spectra of Sm2(Pc)(TPP)2 (1a) (- - -) and Sm2(Pc)2(TPP) (2a) (——) in CH2Cl2.
Ln(acac)3PnH2O (LnsEr, Lu, Y) with (TPP)H2 in a similar manner led to the formation of double-decker complexes Ln(Pc)(TPP) as the sole product [16]. The reactions, however, are in accord with the results reported for the cerium analogue [18]. Mixtures of CeIV(Pc9)(Por), CeIII2(Pc9)(Por)2 and CeIII2(Pc9)2(Por) (Pc9sPc, 2,3,9,10,16,17,
23,24-octamethoxyphthalocyaninate; PorsTPP, TMPP) were obtained by similar treatments on Ce(acac)3PnH2O. However, as mentioned below, the structures of 2a–c and Ce2(Pc)2(Por) are clearly different. These experiments indicate that the yields, distribution and structures of the doubledecker and triple-decker complexes may depend on the nature of the lanthanide metals and the macrocycles used in the reactions. The 1H NMR spectra of the triple-decker complexes Ln2(Pc)(TPP)2 and Ln2(Pc)2(TPP) (LnsSm, Eu) were recorded giving valuable structural information. Due to the strong paramagnetic property of the GdIII ion, the spectra of the analogous gadolinium compounds could not be obtained. NMR data for these heteroleptic triple-decker complexes are scarce and have only been reported for the cerium complexes [18]. Fig. 1(a) shows the 1H NMR spectrum of Eu2(Pc)(TPP)2 (1b) in CDCl3. The broad signals at d 12.87 and 10.72 can be assigned to the a and b protons of the phthalocyanine, respectively. The partially resolved signals at d 11.90, 9.14, 8.11, 6.75 and 4.81 are attributed to the phenyl protons. The presence of five distinct signals for the phenyl groups clearly indicates that there is a restricted rota-
Fig. 3. Observed (bottom) and simulated (top) isotopic distribution for the molecular ions (a) [Eu(Pc)(TPP)]q (3bq), (b) [Eu2(Pc)2(TPP)]q (2bq) and (c) [Gd2(Pc)(TPP)2]q (1cq) in the corresponding FAB-FTICR mass spectra.
Journal: ICA (Inorganica Chimica Acta)
Article: 5336
63
J. Jiang et al. / Inorganica Chimica Acta 255 (1997) 59–64
Table 1 The UV–Vis and near-IR data for the double-decker and triple-decker complexes in CH2Cl2 Compound
lmax (nm) (log e)
Sm2(Pc)(TPP)2 (1a) Eu2(Pc)(TPP)2 (1b) Gd2(Pc)(TPP)2 (1c) Sm2(Pc)2(TPP) (2a) Eu2(Pc)2(TPP) (2b) Gd2(Pc)2(TPP) (2c) Sm(Pc)(TPP) (3a) Eu(Pc)(TPP) (3b) Gd(Pc)(TPP) (3c)
355 (5.02), 418 (5.29), 487 (4.51), 546 (4.09), 605 (4.31) 354 (5.09), 417 (5.35), 488 (4.56), 539 (4.10), 605 (4.33) 353 (5.08), 417 (5.36), 491 (4.61), 556 (4.14), 604 (4.36) 340 (5.16), 414 (4.94), 521 (4.40), 555 (4.33), 617 (4.79), 719 (4.52) 341 (5.18), 411 (4.97), 518 (4.42), 554 (4.33), 616 (4.80), 722 (4.49) 340 (5.16), 411 (4.92), 520 (4.38), 558 (4.29), 617 (4.80), 728 (4.46) 324 (4.76), 406 (4.89), 473 (4.48), 996 (3.37), 1384 (3.60) 319 (4.79), 403 (4.87), 473 (4.47), 1011 (3.35), 1375 (3.53) 316 (4.81), 402 (4.88), 473 (4.50), 1020 (3.31), 1350 (3.54)
tion about the C(meso)–C(phenyl) bond. The remaining singlet at d 3.93 is ascribed to the porphyrin b-pyrrole protons. These results along with the integration are consistent with the triple-decker structure (TPP)Eu(Pc)Eu(TPP) in which two paramagnetic metal centres aresandwichedamong two outer porphyrin and one inner phthalocyanine macrocycles. The 1H NMR spectrum of Eu2(Pc)2(TPP) (2b) is given in Fig. 1(b). The four broad resonances at d 13.04, 11.13, 10.17 and 8.78 having roughly the same intensity may be due to the a and b protons of two inequivalent phthalocyanines. The broad bands at d 12.38, 9.32, 8.18, 6.78 and 4.94 are assigned to the five phenyl protons, while the signal at d 3.21 is ascribed to the pyrrole protons in TPP. The integration shows that there are two Pc moieties and one TPP moiety in the molecule. These NMR data suggest that 2b has theunsymmetrical structure (TPP)Eu(Pc)Eu(Pc). This arrangement of macrocycles is in accord with the structure reported for Ln2(Pc)2(TMPP) (LnsNd, Eu, Gd) [19], but differs from that of the cerium analogues in which the arrangement (Pc)Ce(Por)Ce(Pc) was revealed by X-ray studies [18]. The samarium compounds 1a and 2a also gave 1H NMR spectra which were consistent with the structures (TPP)Sm(Pc)Sm(TPP) and (TPP)Sm(Pc)Sm(Pc), respectively. However, the resonances appeared in a much narrower range (d 6.6–8.3) than those arising from the europium analogues indicating a decrease in paramagnetic shift in the samarium compounds. The electronic absorption spectra of the double-decker complexes Ln(Pc)(TPP) (3a–c) and the triple-decker complexes Ln2(Pc)(TPP)2 (1a–c) and Ln2(Pc)2(TPP) (2a–c) were measured and the data are summarised in Table 1. The UV–Vis and near-IR spectra of compounds 3a–c were very similar to those reported previously and could be assigned in the same way [15,16]. Consistent with the literature results, the lower-energy near-IR band which was attributed to an intramolecular ring-to-ring charge transfer transition was blue-shifted when the ionic radius of the central metal ion decreased from samarium to gadolinium. Fig. 2 shows typical UV–Vis spectra of the samariumcomplexes 1a and 2a, which are closely related to the spectra reported for Ln2(Pc)(TPP)2 (LnsCe, Gd) [15,18] and
Ln2(Pc)2(TMPP) (LnsNd, Eu, Gd) [19], respectively. The absorptions at 340–355 and 411–418 nm can be attributed to the phthalocyanine and porphyrin Soret bands, respectively. The remaining absorptions in the visible region may be due to the Q bands of phthalocyanine and porphyrin in which the lower-energy Q bands are contributed mainly by phthalocyanine. It is noteworthy that the porphyrin Soret band has higher intensity than the phthalocyanine Soret band in 1a, but the order is reversed in 2a as the Pc to TPP ratio increases from 1/2 to 2. The high resolution FAB mass spectra of the compounds 1a–c, 2a–c and 3b were measured using an FTICR mass spectrometer. The molecular ions were detected in all cases. Fig. 3(a) shows the molecular ion region in the spectrum of Eu(Pc)(TPP) (3b) in which distinct isotopic distribution can be observed. The relative abundance of the isotopic peaks is slightly deviated from the simulated spectrum of [Eu(Pc)(TPP)]q as shown in the top-insert. Presumably, a substantial amount of the protonated species [EuH(Pc)(TPP)]q with an isotopic envelope shifted by one mass unit is also present which distorts the isotopic pattern. The co-existence of monocation and protonated species may also occur in the triple-decker complexes. For example, the corresponding isotopic envelope in the spectrum of Eu2(Pc)2(TPP) (2b) is given in Fig. 3(b) (bottom), which Table 2 The FAB-FTICR mass spectral data for the double-decker and triple-decker complexes Compound
Calculated value a (m/z)
Measured value a (m/z)
Error (Dalton)
Sm2(Pc)(TPP)2 (1a) Eu2(Pc)(TPP)2 (1b) Gd2(Pc)(TPP)2 (1c) Sm2(Pc)2(TPP) (2a) Eu2(Pc)2(TPP) (2b) Gd2(Pc)2(TPP) (2c) Eu(Pc)(TPP) (3b)
2038.44 2041.45 2052.46 1938.36 1941.37 1952.39 1277.31
2038.91 2041.63 2052.92 1938.72 1941.70 1952.65 1277.52
0.47 0.18 0.46 0.36 0.33 0.26 0.21
Mass corresponding to the most abundant isotopic peak of the molecular ion.
a
Journal: ICA (Inorganica Chimica Acta)
Article: 5336
64
J. Jiang et al. / Inorganica Chimica Acta 255 (1997) 59–64
also shows a slight deviation from the expected pattern for [Eu2(Pc)2(TPP)]q (top). However, for the samarium and gadolinium triple-decker complexes, it is difficult to determine whether a protonated species is also present as the number of isotopes increases from Eu to Gd and Sm. This is exemplified by Fig. 3(c) showing the pattern arising from Gd2(Pc)(TPP)2 (1c). The mass spectral resultsaretabulated in Table 2. Acknowledgements
Financial support from the Hong Kong Research Grants Council (RGC Earmarked Grant CUHK 311/94P) and The Chinese University of Hong Kong (Incentive Fund 94/95) is gratefully acknowledged. We also thank Professor TienYau Luh for performing the microanalysis and the RGC for providing the funds for the purchase of the Bruker ARX 500 spectrometer through the RGC Central Allocation Scheme 1992. References
[1] K. Kasuga and M. Tsutsui, Coord. Chem. Rev., 32 (1980) 67; M. Hanack, S. Deger and A. Lange, Coord. Chem. Rev., 83 (1988) 115; M. Hanack and M. Lang, Adv. Mater., 6 (1994) 819. [2] J.-J. Andre´, K. Holczer, P. Petit, M.-T. Riou, C. Clarisse, R. Even, M. Fourmigue and J. Simon, Chem. Phys. Lett., 115 (1985) 463; P. Turek, P. Petit, J.-J. Andre´, J. Simon, R. Even, B. Boudjema, G. Guillaud and M. Maitrot, J. Am. Chem. Soc., 109 (1987) 5119; M. Maitrot, G. Guillaud, B. Boudjema, J.-J. Andre´, H. Strzelecka, J. Simon and R. Even, Chem. Phys. Lett., 133 (1987) 59; J. Padilla and W.E. Hatfield, Synth. Met., 29 (1989) F45; M. Bouvet and J. Simon, Chem. Phys. Lett., 172 (1990) 299; K.R. Rickwood, D.R. Lovett, B. Lukas and J. Silver, J. Mater. Chem., 5 (1995) 725. [3] K.L. Trojan, W.E. Hatfield, K.D. Kepler and M.L. Kirk, J. Appl. Phys., 69 (1991) 6007; J.L. Paillaud, M. Drillon, A. De Cian, J. Fischer, R. Weiss and G. Villeneuve, Phys. Rev. Lett., 67 (1991) 244; K.L. Trojan, J.L. Kendall, K.D. Kepler and W.E. Hatfield, Inorg. Chim. Acta, 198– 200 (1992) 795; P. Petit, Synth. Met., 46 (1992) 147. [4] X. Yan and D. Holten, J. Phys. Chem., 92 (1988) 409; O. Bilsel, J. Rodriguez and D. Holten, J. Phys. Chem., 94 (1990) 3508; O. Bilsel, J. Rodriguez, D. Holten, G.S. Girolami, S.N. Milam and K.S. Suslick, J. Am. Chem. Soc., 112 (1990) 4075; O. Bilsel, J. Rodriguez, S.N. Milam, P.A. Gorlin, G.S. Girolami, K.S. Suslick and D. Holten, J. Am. Chem. Soc., 114 (1992) 6528. [5] M.M. Nicholson, in C.C. Leznoff and A.B.P. Lever (eds.), Phthalocyanines: Properties and Applications, Vol. 3, VCH, New York, 1993, pp. 71–117. [6] J.W. Buchler, K. Elsa¨sser, M. Kihn-Botulinski and B. Scharbert, Angew. Chem., Int. Ed. Engl., 25 (1986) 286; J.W. Buchler, Comments Inorg. Chem., 6 (1987) 175; G.S. Girolami, S.N. Milam and K.S. Suslick, J. Am. Chem. Soc., 110 (1988) 2011; J.W. Buchler and B. Scharbert, J. Am. Chem. Soc., 110 (1988) 4272; J.W. Buchler, M. Eberle, P. Hammerschmitt, J. Hu¨ttermann and R. Kappl, Chem. Ber.,
126 (1993) 2619; J.W. Buchler and M. Nawra, Inorg. Chem., 33 (1994) 2830. [7] J.W. Buchler and M. Knoff, in G. Blauer and H. Sund (eds.), Optical Properties and Structure of Tetrapyrroles, Walter de Gruyter, Berlin, 1985, pp. 91–105; J.W. Buchler, A. De Cian, J. Fischer, M. KihnBotulinski, H. Paulus and R. Weiss, J. Am. Chem. Soc., 108 (1986) 3652; J.W. Buchler, J. Hu¨ttermann and J. Lo¨ffler, Bull. Chem. Soc. Jpn., 61 (1988) 71; J.W. Buchler, A. De Cian, J. Fischer, M. KihnBotulinski and R. Weiss, Inorg. Chem., 27 (1988) 339; K. Kim, W.S. Lee, H.-J. Kim, S.-H. Cho, G.S. Girolami, P.A. Gorlin and K.S.Suslick, Inorg. Chem., 30 (1991) 2652; J.W. Buchler, A. De Cian, J. Fischer, P. Hammerschmitt and R. Weiss, Chem. Ber., 124 (1991) 1051; J.W. Buchler, V. Eiermann, H. Hanssum, G. Heinz, H. Ru¨terjans and M. Schwarzkopf, Chem. Ber., 127 (1994) 589; J. Jiang, R.C.W. Liu, T.C.W. Mak, T.W.D. Chan and D.K.P. Ng, Polyhedron, in press, and Refs. therein. [8] R.J. Donohoe, J.K. Duchowski and D.F. Bocian, J. Am. Chem. Soc., 110 (1988) 6119; J.K. Duchowski and D.F. Bocian, J. Am. Chem. Soc., 112 (1990) 3312; J.-H. Perng, J.K. Duchowski and D.F. Bocian, J. Phys. Chem., 94 (1990) 6684; J.-H. Perng, J.K. Duchowski and D.F. Bocian, J. Phys. Chem., 95 (1991) 1319; P.C. Martin, J. Arnold and D.F. Bocian, J. Phys. Chem., 97 (1993) 1332. [9] J.K. Duchowski and D.F. Bocian, J. Am. Chem. Soc., 112 (1990) 8807. [10] For dissimilar phthalocyaninato complexes: Y. Liu, K. Shigehara, M. Hara and A. Yamada, J. Am. Chem. Soc., 113 (1991) 440; A. Pondaven, Y. Cozien and M. L’Her, New J. Chem., 15 (1991) 515; 16 (1992) 711; F. Guyon, A. Pondaven, P. Guenot and M. L’Her, Inorg. Chem., 33 (1994) 4787. [11] For dissimilar porphyrinato complexes: J.W. Buchler, A. De Cian, J. Fischer, P. Hammerschmitt, J. Lo¨ffler, B. Scharbert and R. Weiss, Chem. Ber., 122 (1989) 2219; J.W. Buchler and J. Lo¨ffler, Z. Naturforsch., Teil B, 45 (1990) 531; J.K. Duchowski and D.F. Bocian, Inorg. Chem., 29 (1990) 4158; J.W. Buchler, M. Kihn-Botulinski, J. Lo¨ffler and B. Scharbert, New J. Chem., 16 (1992) 545; G.S. Girolami, P.A. Gorlin, S.N. Milam, K.S. Suslick and S.R. Wilson, J. Coord. Chem., 32 (1994) 173; G.S. Girolami, P.A. Gorlin and K.S. Suslick, Inorg. Chem., 33 (1994) 626; G.A. Spyroulias, A.G. Coutsolelos, C.P. Raptopoulou and A. Terzis, Inorg. Chem., 34 (1995) 2476; G.A. Spyroulias and A.G. Coutsolelos, Inorg. Chem., 35 (1996) 1382. [12] R. Guilard, J.-M. Barbe, A. Ibnlfassi, A. Zrineh, V.A. Adamian and K.M. Kadish, Inorg. Chem., 34 (1995) 1472. [13] M. Lachkar, A. De Cian, J. Fischer and R. Weiss, New J. Chem., 12 (1988) 729; T.-H. Tran-Thi, T. Fournier, A. De Cian, D. Chabach, R. Weiss, D. Houde, C. Pe´pin and L. Dao, Chem. Phys. Lett., 213 (1993) 139. [14] K.M. Kadish, G. Moninot, Y. Hu, D. Dubois, A. Ibnlfassi, J.-M. Barbe and R. Guilard, J. Am. Chem. Soc., 115 (1993) 8153. [15] T.-H. Tran-Thi, T.A. Mattioli, D. Chabach, A. De Cian and R. Weiss, J. Phys. Chem., 98 (1994) 8279. [16] D. Chabach, M. Tahiri, A. De Cian, J. Fischer, R. Weiss and M. El Malouli Bibout, J. Am. Chem. Soc., 117 (1995) 8548. [17] J. Jiang, T.C.W. Mak and D.K.P. Ng, Chem. Ber., 129 (1996) 933. [18] D. Chabach, M. Lachkar, A. De Cian, J. Fischer and R. Weiss, New J. Chem., 16 (1992) 431. [19] M. Moussavi, A. De Cian, J. Fischer and R. Weiss, Inorg. Chem., 25 (1986) 2107. [20] J.G. Stites, C.N. McCarty and L.L. Quill, J. Am. Chem. Soc., 70 (1948) 3142. [21] G.H. Barnett, M.F. Hudson and K.M. Smith, J. Chem. Soc., Perkin Trans. I, (1975) 1401. [22] P.A. Barrett, D.A. Frye and R.P. Linstead, J. Chem. Soc., (1938) 1157. [23] C.-P. Wong, Inorg. Synth., 22 (1983) 156.
Journal: ICA (Inorganica Chimica Acta)
Article: 5336