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The influence of peripheral substitution and the nature of the macroheterocyclic heteroatoms on the basicity of hydrophilic 5,10,15,20-tetraarylporphyrins in the lowest excited singlet S1 state was studied using absorption and fluorescence spectroscopies. The basicity of the porphyrins themselves in the lowest excited singlet S1 state was found to decrease as compared to the ground S0 state. The difference in basicity constants pKa depended on the nature of electronic communication between the macrocycle and peripheral substituents. In the case of an inductive effect of the substituents, the difference in the basicity constants pKa was small, while mesomeric effects led to significant differences in the pKa values. The cooperative nature of protonation, leading to almost simultaneous addition of two protons, was shown to be preserved in both cases. Replacement of a pyrrole with a thiophene in the macroheterocycle led to a decrease in cooperativity in both the ground S0 and the lowest excited singlet S1 states. The basicity constants characterizing the addition of the second and third protons by thia-substituted porphyrin differed significantly in the S1 state (pKa2 – pKa1 = 2), while they were close in the ground state. The activation entropy change ΔΔS‡ upon protonation of the porphyrins in the lowest excited S1 state was compared to that in the ground S0 state. [ABSTRACT FROM AUTHOR]

This review presents all currently known macroheterocyclic compounds that include a bispidine (3,7-diazabicyclo[3.3.1]nonane) fragment in their structure. A classification of bispidine-containing macroheterocycles, which is based on the ring size and the nature of bispidinic nitrogen atoms, is suggested. Synthetic approaches to the studied compounds are classified and considered. The features of the crystal structures and solution behavior of bispidine macroheterocycles are analyzed. Prospects for the development of these organic receptors are proposed.

This review presents all currently known macroheterocyclic compounds that include a bispidine (3,7-diazabicyclo[3.3.1]nonane) fragment in their structure. A classification of bispidine-containing macroheterocycles, which is based on the ring size and the nature of bispidinic nitrogen atoms, is suggested. Synthetic approaches to the studied compounds are classified and considered. The features of the crystal structures and solution behavior of bispidine macroheterocycles are analyzed. Prospects for the development of these organic receptors are proposed. [ABSTRACT FROM AUTHOR]

The geometry and electronic structures of iron(II) complexes with porphyrin (FeP) and tetrabenzoporphyrin (FeTBP) in ground and low-lying excited electronic states are determined by DFT (PBE0/def2-TZVP) calculations and the complete active space self-consistent field (CASSCF) method, followed by the multiconfigurational quasi-degenerate second-order perturbation theory (MCQDPT2) approach to determine the dynamic electron correlation. The minima on the potential energy surfaces (PESs) of the ground (3A2g) and low-lying, high-spin (5A1g) electronic states correspond to the planar structures of FeP and FeTBP with D4h symmetry. According to the results of the MCQDPT2 calculations, the wave functions of the 3A2g and 5A1g electronic states are single determinant. The electronic absorption (UV–Vis) spectra of FeP and FeTBP are simulated within the framework of the simplified time-dependent density functional theory (sTDDFT) approach with the use of the long-range corrected CAM-B3LYP function. The most intensive bands of the UV–Vis spectra of FeP and FeTBP occur in the Soret near-UV region of 370–390 nm. [ABSTRACT FROM AUTHOR]

The title compound, C30H34N2O9 (4), is a product of the Michael reaction of azacrown ether with dimethyl acetylenedicarboxylate modified by an addition of NH3 (aq.) at 298 K. The aza-14-crown-4-ether ring adopts a bowl conformation. The dihedral angle between the planes of the benzene rings fused to the aza-14-crown-4-ether moiety is 8.65 (5)°. The tetrahydropyridine ring has a boat conformation. The molecular conformation is supported by one N—H...O and two C—H...O intramolecular hydrogen bonds. Both heterocyclic and amino N atoms have essentially planar configurations (sums of the bond angles are 359.35 and 358.00°). Compound 4 crystallizes as a racemate consisting of enantiomeric pairs of the 1R,21S diastereomer. In the crystal, molecules of 4 are connected by N—H...O hydrogen bonds, forming chains along [100]. According to the PASS program (computer prediction of biological activities), compound 4 may exhibit antiallergic (72% probability) and antiasthmatic (67%) activity, as well as be a membrane permeability inhibitor (65%).

The title compound, C24H29NO4, is the product of a Petrenko–Kritchenko condensation of 1,5-bis(2-formylphenoxy)-3-oxapentane, pentan-3-one and methylammonium acetate in ethanol. The molecule has mirror symmetry. The aza-14-crown-3 ether ring adopts a bowl conformation stabilized by a weak intramolecular C—H...O hydrogen bond. The conformation of the C—O—C—C—O—C—C—O—C polyether chain is t–g+–t–t–g−–t (t = trans, 180°; g = gauche, ±60°). The dihedral angle between the benzene rings fused to the aza-14-crown-4-ether moiety is 72.68 (4)°. The piperidinone ring adopts a chair conformation. The nitrogen atom has a trigonal–pyramidal geometry, the sum of the bond angles being 335.9°. In the crystal, the molecules are linked by weak C—H...O interactions, forming zigzag chains propagating along the [100] direction.

The title compound, C30H34N2O9 (4), is a product of the Michael reaction of azacrown ether with dimethyl acetylenedicarboxylate modified by an addition of NH3 (aq.) at 298K. The aza-14-crown-4-ether ring adopts a bowl conformation. The dihedral angle between the planes of the benzene rings fused to the aza-14-crown-4-ether moiety is 8.65(5)°. The tetrahydropyridine ring has a boat conformation. The molecular conformation is supported by one N--H...O and two C--H...O intramolecular hydrogen bonds. Both heterocyclic and amino N atoms have essentially planar configurations (sums of the bond angles are 359.35 and 358.00°). Compound 4 crystallizes as a racemate consisting of enantiomeric pairs of the 1R,21S diastereomer. In the crystal, molecules of 4 are connected by N--H...O hydrogen bonds, forming chains along [100]. According to the PASS program (computer prediction of biological activities), compound 4 may exhibit antiallergic (72% probability) and antiasthmatic (67%) activity, as well as be a membrane permeability inhibitor (65%). [ABSTRACT FROM AUTHOR]

The title compound, C24H29NO4, is the product of a Petrenko-Kritchenko condensation of 1,5-bis(2-formylphenoxy)-3-oxapentane, pentan-3-one and methylammonium acetate in ethanol. The molecule has mirror symmetry. The aza-14-crown-3 ether ring adopts a bowl conformation stabilized by a weak intramolecular C--H⋯O hydrogen bond. The conformation of the C--O--C--C--O--C--C--O--C polyether chain is t-g+-t-t-g---t (t = trans, 180°; g = gauche, ±60°). The dihedral angle between the benzene rings fused to the aza-14-crown-4-ether moiety is 72.68 (4)°. The piperidinone ring adopts a chair conformation. The nitrogen atom has a trigonal-pyramidal geometry, the sum of the bond angles being 335.9°. In the crystal, the molecules are linked by weak C--H⋯O interactions, forming zigzag chains propagating along the [100] direction. [ABSTRACT FROM AUTHOR]

A convenient, efficient, and practical method for the synthesis of 1,3,5-thiadiazinan-4-(thi)ones via a multicomponent condensation of urea (or thiourea), formaldehyde and hydrogen sulfide in the presence of a four-fold molar excess of n-BuONa is described. It provides the novel acid- (H2SO4) and base- (n-BuONa)-promoted approach for the one-pot synthesis of the amidine containing macroheterocycles from guanidine and diphenylguanidine. X-ray powder diffraction analysis gave insight into the structure of the 4-methyl-sulfonyl-2H-1,3,5-thiadiazine hydriodide. [ABSTRACT FROM AUTHOR]

• Novel 16- and 20-membered bispidine ferrocenophanes were synthesized. Two approaches for the syntheses of bispidine-ferrocene cyclophanes were reported. Both include the acylation of 1,5-dimethylbispidin-9-one (H 2 Bp) or its pendant amino-armed derivative by 1,1'-ferrocenoyl (Fc(CO) 2) dichloride. The first approach allowed to isolate di-, tri- and pentameric cyclic oligomers of composition (BpFc(CO) 2) n. The second one included the preliminary functionalization of H 2 Bp by N-protected glycine followed by deprotection and cyclization with Fc(COCl) 2. The crystal structure of two new bispidine-ferrocene cyclophanes was established by single-crystal X-ray study. This study revealed the anti-conformation of amido-groups attached to the bispidine nitrogen atoms for both molecules. Various NMR techniques were applied to study the solution behavior of the macrocycles; the predominant anti-conformation in solution was also proved. The acyclic model compound Bp(FcCO) 2 also showed only anti-conformer as revealed by VT-NMR and X-ray studies. Cyclic voltammetry study showed the difference in oxidation potentials of the Fc moiety within the row Bp(FcCO) 2 – (BpFc(CO) 2) 2 – (BpFc(CO) 2) 3 with splitting of the oxidation curve in two later cases. The results obtained in this work will find an application in design and study of novel bispidine-ferrocene cyclophanes for the purposes of supramolecular sensing and catalysis. [Display omitted] [ABSTRACT FROM AUTHOR]

The title compound, C 30 H 34 N 2 O 9 ( 4 ), is a product of the Michael reaction of aza-crown ether with dimethyl acetyl-enedi-carboxyl-ate modified by an addition of NH 3 (aq.) at 298 K. The aza-14-crown-4-ether ring adopts a bowl conformation. The dihedral angle between the planes of the benzene rings fused to the aza-14-crown-4-ether moiety is 8.65 (5)°. The tetra-hydro-pyridine ring has a boat conformation. The mol-ecular conformation is supported by one N-H⋯O and two C-H⋯O intra-molecular hydrogen bonds. Both heterocyclic and amino N atoms have essentially planar configurations (sums of the bond angles are 359.35 and 358.00°). Compound 4 crystallizes as a racemate consisting of enanti-omeric pairs of the 1 R ,21 S diastereomer. In the crystal, mol-ecules of 4 are connected by N-H⋯O hydrogen bonds, forming chains along [100]. According to the PASS program (computer prediction of biological activities), compound 4 may exhibit anti-allergic (72% probability) and anti-asthmatic (67%) activity, as well as be a membrane permeability inhibitor (65%).

The title compound, C 24 H 29 NO 4 , is the product of a Petrenko-Kritchenko condensation of 1,5-bis-(2-formyl-phen-oxy)-3-oxa-pentane, pentan-3-one and methyl-ammonium acetate in ethanol. The mol-ecule has mirror symmetry. The aza-14-crown-3 ether ring adopts a bowl conformation stabilized by a weak intra-molecular C-H⋯O hydrogen bond. The conformation of the C-O-C-C-O-C-C-O-C polyether chain is t-g + -t-t-g - -t (t = trans , 180°; g = gauche , ±60°). The dihedral angle between the benzene rings fused to the aza-14-crown-4-ether moiety is 72.68 (4)°. The piperidinone ring adopts a chair conformation. The nitro-gen atom has a trigonal-pyramidal geometry, the sum of the bond angles being 335.9°. In the crystal, the mol-ecules are linked by weak C-H⋯O inter-actions, forming zigzag chains propagating along the [100] direction.