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Diels–Alder reaction between tribenzo[b,g,l]thiopheno[3,4-q]porphyrazine and dimethyl acetylenedicarboxylate at ca. 200 °C produced a substituted tribenzo[b,g,l]porphyrazine and 3:1 unsymmetrically substituted phthalocyanine, which were characterized by UV-VIS, MCD, NMR, and mass spectroscopies.

In the two independent but very similar mol-ecules of the title compound, C(11)H(14)N(2)O(6), both nucleobase fragments are nearly planar (both within 0.01 Å) while the furan-ose rings exhibit (2)E-endo envelope conformations. In the crystal, the two 3'-O-acetyl-2'-de-oxy-uridine mol-ecules form a pseudosymmetric dimer of two bases connected via two nearly identical resonance-assisted N-H⋯O hydrogen bonds. The resulting pair is further connected with neighboring pairs via two similar O-H⋯O bonds involving the only hydroxyl group of the 2'-de-oxy-furan-ose fragment and the remaining carbonyl oxygen of the nucleobase. These inter-actions result in the formation of an infinite 'double band' along the b axis that can be considered as a self-assembled analogue of a polynucleotide mol-ecule with non-canonical Watson-Crick base pairs. The infinite chains of 3'-O-acetyl-2'-de-oxy-uridine pairs are additionally held together by C-H⋯O inter-actions involving C atoms of the uracyl base and O atoms of carbonyl groups. Only weak C-H⋯O contacts exist between neighboring chains.

Methods for the synthesis of various coordination compounds of iron phthalocyanines and their closest structural analogues, viz., iron porphyrazines and naphthalocyanines, their structures, properties and applications are surveyed. The bibliography includes 230 references.

Room-temperature synthesis of phthalocyanines (pcs) by condensation of phthalonitriles in the presence of solid sodium methoxide in THF is proposed for the synthesis of metal-free pcs with temperature- and/or base-sensitive substituents. The addition of metal salts after metal-free pc formation in the same vessel produces metallopcs in moderate to high (ca. 30–90%) yields.

The title compound, [Fe(C(5)H(5))(C(9)H(5))], crystallizes in a form of a π-π-stacked assembly formed as a result of strong inter-molecular π-π inter-actions between (a) the triple bonds of two neighboring butadiyne substituents overlapping in a 'head-to-tail' fashion [characterized by C⋯C short contacts of 3.622 (5), 3.567 (6) and 3.556 (6) Å] and (b) the triple bonds of the butadiyne substituent and substituted cyclo-pendadiene ring of neighboring mol-ecules [C⋯C = 3.474 (5) and 3.492 (6) Å]. The linear butadiyne substituent has alternating C-C triple and single bonds, while the unsubstituted cyclo-penta-diene ring is slightly positionally disordered (although the structure reported here was solved as non-disordered) and retains a close to eclipsed conformation.

In the title compound, C(20)H(14)BNO(2), the B atom has a tetra-hedral geometry with two short B-O and two long B-C and B-N bonds, revealing a significant difference between C(ar)-O-B and C(alk-yl)-O-B bond distances. Inter-molecular Ar-H⋯O hydrogen bonds and strong π-π inter-actions (3.368 Å) between aromatic cores of neighbouring mol-ecules result in hexa-gonal channels along the crystallographic c axis, which are potentially accessible for small mol-ecules.

The A-ring oxidation/contraction of 3-oxotriterpenoids was developed as a two-step and “one pot” process. A benzylic acid type rearrangement of triterpenoid diosphenols gives (S)- as major and (R)-α-hydroxycarboxylic acids as minor reaction products. The absolute configurations were determined from the X-ray crystal structure analysis. The mechanism of ring contraction was modelled computationally at the DFT and MP2 levels of theory. The tautomeric triterpenoid A-seco δ-oxocarboxylic acids and A-ring hydroxy lactones formed after deep oxidation/acidification of 3-oxotriterpenoids.

Absorption spectra of several free base triarylcorroles were investigated by MCD spectroscopy. The MCD spectra exhibit unusual sign-reverse (positive-to-negative intensities in ascending energy) features in the Soret- and Q-type band regions, suggesting a rare ΔHOMO < ΔLUMO relationship between π and π* MOs in the corrole core.

The mononuclear monooxomolybdenum(VI) complex hydrotris(3,5-dimethyl-1-pyrazolyl)borato(bis-4-ethoxyphenolato)oxomoylybdenum(VI) cation, [LMoVIO(p-OC6H4-OC2H5)2]+, where L- = hydrotris(3,5-dimethyl-1-pyrazolyl)borate, has been synthesized by chemical and electrochemical oxidation from the corresponding neutral oxomolybdenum(V) species, LMoVO(p-OC6H4-OC2H5)2. The molybdenum(VI) species has been characterized by NMR, IR, and resonance Raman spectroscopies, mass spectrometry, and electronic spectroscopy. Acetonitrile solutions of cationic [LMoVIO(p-OC6H4-OC2H5)2]+ react with tertiary phosphines (PR3) to generate phosphineoxide-bound adducts, [LMoIV(OPR3)(p-OC6H4-OC2H5)2]+, which subsequently generate the cationic desoxo species, [LMoIV(p-OC6H4-OC2H5)2]+ and OPR3. In the presence of water and an oxidizing agent the desoxo species generates the monooxomolybdenum(V), LMoVO(p-OC6H4-OC2H5)2, and completes the catalytic cycle. The oxygen atom transfer reaction has been probed by isotope-labeling experiments, vibrational spectroscopies, and mass spectrometry. This study describes an analogue complex that can exhibit all important processes of the catalytic cycle involving monooxomolybdenum(VI) and desoxomolybdenum(IV) centers.

Crystal structures of potassium, rubidium, and cesium triphenylcyanoborates were investigated in order to explain high selectivity of triphenylcyanoborate ion (“caesignost”) as an agent for cesium precipitation. Alkali metal ions have substantially different coordination modes with triphenylcyanoborate ion coordinated to the cyano group in the end-on or side-on motif and to the phenyl group in the π–M+ motif.

Redox properties of several transition-metal MTFcP complexes (TFcP2− = 5,10,15,20-tetraferrocenylporphyrin, M = Co2+, Ni2+, Cu2+, and Zn2+) were investigated using electrochemical (CV and DPV), spectroelectrochemical, and chemical oxidation approaches. Electrochemical experiments conducted in a low-polarity solvent using a non-coordinating electrolyte are crucial for the sequential oxidation of ferrocene substituents along with porphyrin-based single-electron oxidation and reduction processes. The first ferrocene oxidation process in all MTFcP complexes is separated by at least 140 mV from the next three ferrocene based oxidations. The second, third, and fourth redox processes in the ferrocene region are more closely spaced, with the largest separation observed in CuTFcP and CoTFcP complexes. Mixed-valence compounds were observed and characterized by spectroelectrochemical and chemical oxidation approaches. In all cases, intervalence charge transfer (IVCT) bands were detected confirming the existence of the iron-based mixed-valence [MTFcP]n+ (n = 1–3) species and suggesting long-range metal–metal coupling in the target systems. The resulting data from the mixed-valence [MTFcP]n+ (n = 1–3) complexes matched very closely to the metal-free poly(ferrocenyl)porphyrins previously reported and were assigned as Robin and Day Class II mixed-valence compounds. In the case of CoTFcP, the selective oxidation of a central metal was also demonstrated in the presence of the strong ligand-field anions using oxygen as an oxidant.

A tetraazaporphyrin (TAP) prepared by condensation of 1-ferrocenyl-1,2,2-tricyanoethylene in the presence of magnesium shows an intense, broad near-IR band in the 700–1300 nm region, which may be ascribed to charge-transfer transitions from the ferrocenyl moiety (substituents) to the TAP ligand.

Diels–Alder reaction between tribenzo[b,g,l]thiopheno[3,4-q]porphyrazine and dimethyl acetylenedicarboxylate at ca. 200 °C produced a substituted tribenzo[b,g,l]porphyrazine and 3:1 unsymmetrically substituted phthalocyanine, which were characterized by UV-VIS, MCD, NMR, and mass spectroscopies.

Low-symmetrical phthalocyanines (Pcs) 2-5 prepared by mixed condensation of tetraphenylphthalonitrile and 4-phenylthiophthalonitrile in the presence of a copper salt, show spectroscopic, electrochemical, and molecular model indications which suggest varying degrees of non-planar distortions of the Pc plane and unexpected S1 state degeneracy.

In the title compound, C11H12INO3, molecules are linked into one-dimensional chains along the crystallographic a axis by strong intermolecular N—H...O hydrogen bonds. The one-dimensional chains are additionally stabilized by weak intermolecular Car—H...O interactions. Unlike its iodine(V) analogues, the organic chain substituent in the title iodine(I) compound is not coplanar with the aromatic core but exhibits a C—C—C—O torsion angle of 50.3 (7)°.

Single crystal X-ray structures of two 2-iodylbenzenesulfonamides reveal a combination of intra- and intermolecular I⋯O interactions leading to a typical hexacoordinated and a unique heptacoordinated iodine(V) center.

A stable molybdenum(V) complex, LMoOCl2 (where L is hydrotris(3,5-dimethylpyrazolyl)borate), has been oxidized under mass spectrometric conditions. The oxidized species reacts with tertiary phosphines and the products have been detected by mass spectrometry. The product distribution has been followed by isotope labeling experiments, and energy dependent electrospray mass spectrometry. These experiments reveal not only oxygen atom transfer but also loss of a chlorine atom from the resulting species.

A large number of para-substituted benzene thiols and the corresponding disulfides were synthesized and characterized by 1H NMR, 13C NMR, and IR spectroscopies. Geometries of all sixteen thiols and fourteen disulfide compounds were optimized at the B3LYP/6-31G(d) level, while the electronic structure and the 13C isotropic shifts were calculated by ab initio Hartree-Fock method coupled with the Gauge-Independent Atomic Orbital (GIAO) algorithm and a 6-31+G(d,p) basis set. The calculated 13C NMR isotropic shifts exhibit admirable agreement (δ rmsd ∼4.6 ppm) with the experimental data. The chemical shift of para-substituted carbon showed a linear correlation with Hammett constants (σp and σp+). Using this methodology the σp+ constants for the dendritic ligands have been estimated to be 0.25 and 0.24 for 2(n) and 2(o), respectively. In addition, the NBO charges on the sulfur atoms shows a latent response with the σp+ parameter. The atomic charge on the thiophenolato sulfur is invariant with the electron withdrawing ability of the substituents, however, the charge increases with increasing electron-withdrawing power.

This review summarizes the synthetic strategies for substituted phthalonitriles and phthalocyanines. Preparation of alkyl-, aryl-, halo-, nitro-, alkoxy-, aryloxy-, alkylthio-, arylthio-, and amino- substituted phthalocyanines along with the derivatives of phthalocyanine carboxylicand sulfoacids is overviewed. Influence of the substituents on the position of Q-band in UV-vis spectra of substituted phthalocyanines is also briefly discussed.

We present the crystal structure of pcFe(4-methylpiperidine)2 as a first example of a low-spin iron(II) phthalocyanine (pc) complex bis-axially coordinated by aliphatic amines. It is shown that electronic rather than steric effects are responsible for the elongation of the Fe−N(axial) bond in pcFeL2 complexes. Using density functional theory, the electronic structures as well as Mossbauer isomer shifts and quadrupole splittings have been investigated for a large number of pcFeL2 and pcFeL1L2 complexes, in which the axial ligands have varying electronic and steric properties. The electron charge densities and electric field gradients at the iron ion were evaluated using a locally dense basis approach with Wachters’ all-electron basis set for the iron ion, the 6-311++G(2d) basis set for atoms directly bonded to the iron ion, the 6-31G(d) basis set for atoms two bonds away from the iron ion, and the 3-21G* basis set for all other atoms. A good correlation between the theoretical and experimental isomer shifts and quadrupole splittings has been observed for all the complexes tested. It has also been shown that the proposed model for the calculation of Mossbauer spectral parameters is adequate for the evaluation of the axial ligand conformation in cases of conformational flexibility in pcFeL2 complexes.