Heteroleptic Rare Earth Double-Decker Complexes with Porphyrinato and 2,3-Naphthalocyaninato Ligands − Preparation, Spectroscopic Characterization, and Electrochemical Studies

Abstract

A series of RE(Nc)(TBPP) (1−12) complexes [RE = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Y, Ho, Er, Tm; Nc = 2,3‐naphthalocyaninate; TBPP = meso‐tetrakis(4‐tert‐butylphenyl)porphyrinate] and Eu[Nc(tBu)4](TClPP) [Nc(tBu)4 = tetra(tert‐butyl)‐2,3‐naphthalocyaninate; TClPP = meso‐tetrakis(4‐chlorophenyl)porphyrinate] (13) have been prepared by a one‐pot procedure which involves the treatment of RE(acac)3·nH2O (acac = acetylacetonate) with the corresponding metal‐free porphyrins and naphthalonitriles in the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in n‐octanol. These novel double‐deckers have been spectroscopically characterized. A one‐electron reduction and three one‐electron oxidations have been revealed by electrochemical methods. The potentials of all these processes depend linearly on the ionic radii of the central metal ions, giving a relatively large potential difference (0.50−0.57 V) between the first oxidation and the first reduction processes.

A series of homoleptic bis(phthalocyaninato) rare earth sandwich complexes with large two-photon absorption cross-section

“…As shown in Table 1, the ionic radii of Ce(Ⅲ), Sm(Ⅲ) and Lu(Ⅲ) are 114 pm, 109 pm and 97 pm respectively [47,48], and the 2PA cross-section of Ce(OOPc) 2 (1), Sm(OOPc) 2 (2), Lu(OOPc) 2 (3) is 3.5×10 4 GM (1), 9.3×10 4 GM (2) and 1.2×10 5 GM (3) at the wavelength of 800 nm respectively. Previous research has proved that the π-π interaction between the two phthalocyaninato rings becomes stronger with the decrease of the rare earth atomic radius.…”

Sandwich complexes of naphthalocyanine with the rare earth metals

“…To increase the yield of target mixed ring doubledeckers and simplify the purification procedure, Jiang and co-workers developed a new synthetic pathway for both mixed (phthalocyaninato)(porphyrinato) and heteroleptic bis(phthalocyaninato) rare earth complexes which involves a cyclic tetramerization of dicyanobenzenes using M(ring)(acac) (M = rare earths; ring = Por, Pc) as the template in refluxing n-pentanol. This method has now been extended to the Nc ligand with the preparation of a series of mixed (naphthalocyaninato)(porphyrinato) rare earth complexes in high boiling point n-octanol [23][24][25][26][27]. So there is a significant difference between the Pc' and Nc' systems in the temperatures required for the syntheses.…”

“…A one-pot procedure involving the metal-free porphyrin H 2 (Por), M(acac) 3 . nH 2 O, naphthalonitrile, and DBU in n-octanol leads easily to the desired mixed ring double-decker as the sole product in moderate to good yields (Scheme 3) [24][25][26]. Similar to M(Por) 2 [4] and M(Nc*) 2 [14] but in contrast to M(Pc) 2 [2] and M[Pc(OC 8 H 17 ) 8 ] 2 [2], the yields of these mixed sandwiches decrease steadily with the contraction in size of the central metal ion, for example for M(TBPP)(Nc), from 73% for M = La to 29% for M = Tm [24], probably due to an increase in steric compression between the two macrocyclic ligands.…”

“…Although naphthalocyanine-containing sandwich complexes have been known for some time, most studies have been limited to the homoleptic and heteroleptic naphthalocyanine-containing lutetium complexes [5][6][7][8][9][10][11][12][13]. Sandwich-type naphthalocyanine complexes of rare earth metals other than lutetium have appeared only recently [14][15][16][17][18][19][20][21][22][23][24][25][26][27].…”

Spectroscopic and structural characteristics of Langmuir–Blodgett films of bis[2,3,9,10,16,17,24,25-octakis(octyloxy)phthalocyaninato] rare earth complexes

“…This series of tetrapyrrole derivatives can form complexes with almost the complete Periodic Table of elements. In particular, sandwich-type complexes of phthalocyanines with large metal ions such as rare earth, actinide, early transition, and main group metals have been obtained [6][7][8][9][10]. The rare earth sandwich complexes have attracted great attention due to their possible applications in molecular electronics, molecular optronics, and molecular iono-electronics [11].…”