Tetrakis(thiadiazole)porphyrazines. 1. Syntheses and Properties of Tetrakis(thiadiazole)porphyrazine and Its Magnesium and Copper Derivatives

Abstract

The new macrocycle tetrakis(thiadiazole)porphyrazine, TTDPzH 2 , has been prepared, in CF 3 COOH, from its corresponding Mg(II) derivative, [TTDPzMg(H 2 O)]‚CH 3 COOH, which, in turn, is obtained by the reaction of magnesium(II) propylate and 3,4-dicyano-1,2,5-thiadiazole. The Mg(II) complex is also used for the preparation of the Cu(II) derivative, TTDPzCu, by reaction with copper acetate in CF 3 COOH. An alternative preparation allows the Cu(II) complex to be obtained from the metal-free macrocycle and Cu(OCOCH 3 ) 2 in pyridine. Like the Mg(II) complex, TTDPzH 2 and TTDPzCu are obtained as solvated species (carboxylic acid, water). Practically complete elimination of the solvent molecules can be achieved by heating the species under vacuum (10 -2 mmHg) at 300-310°C, only the Mg(II) complex retaining water. TTDPzH 2 and TTDPzCu can also be obtained by sublimation under vacuum (10 -2 mmHg, 400-450°C) from the parent solvated complexes. IR spectra in the range 4000-200 cm -1 allow easy identification of the different species. Deuteration of TTDPzH 2 has allowed assignments of the NH stretching and bending vibrations. The UV-visible solution spectra in different media all exhibit intense absorptions in the Soret-band (300-400 nm) and Q-band (600-700 nm) regions, showing strong resemblance to those of their corresponding phthalocyanine analogues. A detailed analysis of the spectral behavior allows the electronic structure of the TTDPz macrocyclic ring to be adequately depicted. IntroductionSome of the most recent research work on the synthesis, chemical-physical characterization, and reactivity of metal phthalocyanines developed by our and joint laboratories has shown the capacity of different diphthalocyanine molecular units, i.e., Pc 2 M (M ) Ti(IV), Sn(IV)), 1 (PcFe) 2 C, 2 and (PcRu) 2 , 3 to result in the formation of linearly elongated electrically conductive materials upon oxidation with I 2 or O 2 , and the role played by the metal centers and by the close π-π contacts of the adjacent Pc rings in the efficiency of charge transfer along the chained systems has been thoroughly examined. 1-3 We have now started an investigation on porphyrazine (Chart 1a) and substituted porphyrazines and their metal derivatives, a class of materials far less studied, though recently the object of growing interest, 4 than their closely related phthalocyanine 5 (Chart 1b) and porphyrin analogues, 6 and have focused our attention on the synthesis of tetrakis(thiadiazole)porphyrazine, TTDPzH 2 (Chart 2a) and its selenium analogue and their metal derivatives as well, because electron-rich and soft substituents such as S or Se inserted into the proximity of the central

Heterocyclic Subphthalocyanine Analogue – Boron(III) Subporphyrazine with Fused 1,2,5-Thiadiazole Rings

“…[24] In the present communication we report the synthesis of 1,2,5-thiadiazole fused subporphyrazine with the central B III Cl unit, [(SN 2 ) 3 SubPABCl]. Boron trichloride (2 ml of 1 M solution in p-xylene, Aldrich) was added to freshly sublimed 1,2,5-thiadiazole-3,4-dicarbonitrile [25] (2 mmol). The reaction mixture immediately became orange and upon heating thickened and then turned dark green, the colour finally changing to dark violet upon refluxing under Ar for 1 h. Significant UV-visible spectral changes were observed during the reaction process.…”

Templating effects of tetrakis(thiadiazole)porphyrazine on the structure and optical properties of copper phthalocyanine thin films

“…H2TTDPz was prepared as described in the literature [10]. The obtained H2TTDPz was purified by vacuum sublimation with a continuous N2 gas flow (40-50 ml min -1 ).…”

“…The MTTDPz family was synthesized by Ercolani, Stuzhin and their coworkers [10,11], and in our previous works, we determined the crystal structures of the M=H2, VO, Fe, Co, Ni, Cu and Zn derivatives [12][13][14]. The derivatives were found to form multi-dimensional structures that could be essentially classified into three polymorphs: the α, β, and γ forms.…”

Highly-oriented molecular arrangements and enhanced magnetic interactions in thin films of CoTTDPz using PTCDA templates

“…7,8 The obtained CoTTDPz was purified by vacuum sublimation with a continuous N 2 gas flow (40-50 ml min À1 ). Commercial PTCDA (purity 498%) was used without further purification.…”