A novel fluorescein-porphyrinatozinc(II) hybrid: synthesis and its supramolecular self-assembly with imidazolyl-linked porphyrinatomanganese(III) by coordinative bonding

A novel fluorescein–porphyrinatozinc(II) hybrid, Zn(Fl–PPTPP), was synthesized and characterized by u.v.–vis., i.r., ¹H-n.m.r, ESMS and elemental analyses. The supramolecular self-assembly of Zn(Fl–PPTPP) with an imidazolyl-linked porphyrinatomanganese(III), Mn^(III)(p-ImBPTPP)Cl, complex has been studied by fluorescence spectroscopic titration, VPO measurements and ESMS, which indicates that the formation of the Zn(Fl–PPTPP)–Mn^(III)(p-ImBPTPP)Cl. supramolecular complex is driven by coordinative bonding formed by the coordination of imidazolyl group in Mn^(III)(p-ImBPTPP)Cl to Zn(II) in Zn(Fl–PPTPP). The association constant of the supramolecular complex was calculated from the fluorescence spectroscopic titration data. It was found that the conformation of the Zn(Fl–PPTPP)–Mn^(III)(p-ImBPTPP)Cl supramolecular complex, the steric hindrance and the electronic effect of the fluorescein group linked to porphyrin through a flexible long alkoxy chain are all acting on the association constant of the Zn(Fl–PPTPP)–Mn^(III)(p-ImBPTPP)Cl supramolecular complex. It seems that the steric hindrance and the electronic effect of the fluorescein group are the primary factors effecting the association constant of Zn(Fl–PPTPP)–Mn^(III)(p-ImBPTPP)Cl supramolecular complex, especially the electronic effect of the fluorescein group, which is the reason for the association constant of Zn(Fl–PPTPP)–Mn^(III)(p-ImBPTPP)Cl being smaller than that of ZnTPP–Mn^(III)(p-ImBPTPP)Cl.     

Novel complexes of 5-(4-carboxyl)phenylene-methanaminophenyl-10,15,20-tri-phenylporphyrin with zinc(II), iron(III), manganese(III) and zinc(II)–iron(III), zinc(II)–manganese(III) supramolecular self-assembly by hydrogen bonding

5-(p-Carboxyl)phenylene-methanaminophenyl-10,15,20-triphenylporphyrin (p-CPTPP) and its Zn^II[Zn(p-CPTPP)], Fe^III[Fe^III(p-CPTPP)Cl], Mn^III[Mn^III(p-CPTPP)Cl] complexes were prepared and characterized by elemental analysis, ¹H-n.m.r., i.r. and u.v.–vis. spectroscopy. The behaviour of the supramolecular self-assemblies, Zn(p-CPTPP)–Fe^III(p-CPTPP)Cl and Zn(p-CPTPP)–Mn^III(p-CPTPP)Cl, were studied by steady-state fluorescence spectroscopic titration and u.v.–vis. spectra. The formation constants were determined from the data of fluorescence spectroscopic titration. The fact that the Zn(p-CPTPP)–Mn^III(p-CPTPP)Cl system has a higher formation constant than the Zn(p-CPTPP)–Fe^III(p-CPTPP)Cl system is discussed.     

Mixed-ligand complexes of gold(I) and silver(I) with heterocyclic thiones

Summary Novel mixed-ligand complexes of Ag¹ and Au¹ containing triphenylphosphine (TPP) and heterocyclic thiones, of general formula [TPP–M–L]Cl and [(TPP)₂–M–L]Cl, where L=imidazolidine-2-thione (Imt), 1,3-diazinine-2-thione (Diaz) or N-isopropylimidazolidine-2-thione (iPrImt) have been prepared. The spectroscopic data are consistent with S-donation in all complexes. The magnitude of high-field shift in carbon-13 n.m.r. of the thioureide carbon on complexation is interpreted in terms of coordination geometry around the metal atoms. The mixed-ligand complexes are structurally similar to some of the commonly used antiarthritic Au¹ drugs and are thus potentially useful in chemotherapy.     

A fluorescence study of tetraphenylporphyrinatozinc(II)/imidazolyl-linked porphyrinatoiron(III) systems

The fluorescence spectra of porphyrinatozinc(II)/iron(III) systems which consisted of tetraphenylporphyrinatozinc(II) and three kinds of imidazolyl-linked porphyrinatoiron(III) have been studied. An efficient fluorescence quenching of tetraphenylporphyrinatozinc(II) in the system was observed. Addition of a stronger organic base, such as piperdine, to the system can displace imidazolyl-linked porphyrinatoiron(III) and the fluorescence of the system restored partly. All these indicate the formation of porphyrinatozinc(II)/iron(III) supramolecular complex and coordination bonding formed by the coordination of imidazolyl group in imidazolyl-linked porphyrinatoiron(III) to Zn(II) in tetraphenyl-porphyrinatozinc(II) is the driving force of the supramolecular self-assembly. The association constants of the supramolecular complexes were calculated from the fluorescence spectroscopic titration data, and the differences among the association constants of the supramolecular complexes are discussed on the basis of the conformations which are dependent on the length of alkoxy chain linking imidazolyl group to porphyrinatoiron(III).     

Synthesis and Characterization of New Conjugated Fluorenyl‐Porphyrin Dendrimers for Optics

A new family of conjugated meso‐tetraphenylporphyrin‐based dendrimers with four ( TPP1 , TPP2 ), eight ( TPP3 , TPP4 , TPP5 ) and up to sixteen ( TPP6 ) fluorenyl groups has been synthesized and fully characterized. These tetraphenylporphyrin‐cored dendrimers present peripheral alkynyl π‐conjugated dendrons with fluorenyl termini. The meso‐aryl rings of these porphyrins are functionalized either in para‐ ( TPP1 , TPP2 , and TPP3 ) or meta‐positions ( TPP4 , TPP5 , and TPP6 ). Their detailed luminescence properties are discussed in reference to two porphyrins lacking fluorenyl dendrons ( TPP ‐ H_1,2,3 and TPP ‐ H_4,5,6 ). A strong dependence of their luminescence quantum yield and lifetime on their structures is stated, their nonlinear optical properties were also discussed.     

The thermodynamic studies of the molecular interactions of methyltin(IV) tribromide with free base meso-tetraarylporphyrins

The thermodynamic parameters for the interactions of MeSnBr₃ with para- and meta-substituted meso-tetraphenylporphyrins (H₂T(4-X)PP; X=OCH₃, CH₃, H, Cl, NO₂ and H₂T(3-X)PP; X=CH₃, Cl) have been studied. The formation constants have been elucidated by using spectrophotometric titration and computer squad program data refinement. The adducts of composition 2:1 and 1:1 of MeSnBr₃ to H₂T(4-X)PP with stability constants K₁ and K₂ coexist in solution, but meta-substituted porphyrins form adducts of the composition 1:1 of MeSnBr₃ to H₂T(3-X)PP with stability constant K₁. Formation constants decrease with decreasing electron donation of para-substituted porphyrins as follow: H₂T(4-CH₃O)PP>H₂T(4-CH₃)PP>H₂TPP>H₂T(4-Cl)PP>H₂T(4-NO₂)PP. Despite the electron donation of the methyl group, H₂T(3-Cl)PP forms more stable adducts than H₂T(3-CH₃)PP with MeSnBr₃.     

Mixed-ligand complexes of copper(I) with heterocyclic thiones

Summary Novel mixed-ligand copper(I) complexes of general formula [TPP–Cu–(L)Cl] or [TPPhos–Cu–(L)Cl], where TPP=triphenylphosphine, TPPhos=triphenylphosphate and L=imidazolidine-2-thione [Imt],N-propylimidazolidice-2-thione [PrImt],N-i-propylimidazolidine-2-thione [iPrImt], and 1,3-diazinine-2-thione [Diaz] and bis coniplexes of formula [(L)₂CuCl] where L=[PrImt] and [iPrImt] have been prepared and characterized by electronic, vibrational and n.m.r. spectroscopy. The spectral data are consistent with S-donation of thiones. The magnitude of upfield shift in¹³Cn.m.r. of the thionreide carbon on complexation has been interpreted in terms of coordination geometry around the metal stoms. X-ray structure analysis agrees with the conclusions from the spectroscopic measurements. The structure of [(PrImt)₂CuCl] revealed three-coordinated copper(I) with crystal data:a=14.106(4),b=14.380(2),c=19.024(3) A, =108.8(2)°,z=8 and space group P2/c.     

Specific retention behaviour of metal (III) tetraphenylporphyrins in non-aqueous,reversed high-performance liquid chromatography

Summary The Co(II), Ni(II), Fe(III) and V(IV) complexes of tetraphenylporphine (TPP) can be eluted at short retention times from a LiChrosorb RP-18 column with pure ethanol. However, both Mn(III) and Co(III) complexes of metal TPP chloride type are so strongly retained on the column that they cannot be eluted. While the retention of other metal teraphenylporphine complexes was not affected, that of the metal(III) complexes of the TPP chloride type especially MnTPPCl and CoTPPCl, decreases dramatically with an increase in the concentration of NH₄Cl added into the mobile phase; a linear relationship between logk' and log[NH₄Cl], with the slope of about–1, has been observed for these two metal(III) complexes in the NH₄Cl concentration range from 2.5×10^–4 to 1.3×10^–2 mol/l. Thus, the specific control of the retention of the metal(III) complexes is enabled by conditioning the NH₄Cl content of the mobile phase, and the chromatographic separation is demonstrated.     

A carboxyl porphyrin zinc(II)–copper(II) supramolecular system with fluorescence strengthening properties

The supramolecular self-assembly behavior, by hydrogen-bonding, of zinc(II) [Zn(p-CPTPP)], copper(II) [Cu^II-(p-CPTPP)] complexes [(p-CPTPP) = 5-(p-carboxyl)-phenylene-methanamidophenyl-10,15,20-triphenylporphyrin] were studied by fluorescence spectroscopic titration and by u.v.–vis. spectra. The fluorescence strengthening character was observed in the Zn(p-CPTPP)/Cu^II(p-CPTPP) system in a fluorescence spectroscopic titration experiment. The formation constant was determined from the fluorescence spectroscopic titration data and the fluorescence strengthening property of the system was discussed using the fluorescence spectrum of the charge-separated state obtained by the method of spline wavelet least squares.     

The molecular structure of high‐spin (S = ) manganese(II) phthalocyanine in tetrabutylammonium bromido(phthalocyaninato)manganese(II)

The title complex salt, (C₁₆H₃₆N)[MnBr(C₃₂H₁₆N₈)] or (TBA)[Mn^IIBr(Pc)] (TBA is tetrabutylammonium and Pc is phthalocyaninate), has been obtained as single crystals by the diffusion technique and its crystal structure was determined using X‐ray diffraction. The high‐spin (S = ) [Mn^IIBr(Pc)]⁻ macrocycle has a concave conformation, with an average equatorial Mn—N(Pc) bond length of 2.1187 (19) Å, an axial Mn—Br bond length of 2.5493 (7) Å and with the Mn^II cation displaced out of the 24‐atom Pc plane by 0.894 (2) Å. The geometry of the Mn^IIN₄ fragment in [Mn^IIBr(Pc)]⁻ is similar to that of the high‐spin (S = ) manganese(II) tetraphenylporphyrin (TPP) in [Mn^II(1‐MeIm)(TPP)] (1‐MeIm is 1‐methylimidazole).     

Interaction of a new cobalt(II) complex of five-coordinated chiral porphyrin with calf thymus DNA

A new template-directed chiral porphyrin [(TPP)Co(Trp)], where TPP = tetraphenylporphyrin and Trp = 1-tryptophan, was prepared and characterized by various physico-chemical methods. Interaction of [(TPP)Co(Trp)] with calf thymus DNA was studied by u.v.–vis. spectroscopy and cyclic voltammetry. The complex [(TPP)Co(Trp)], after interaction with calf thymus DNA, shows a shift in the absorption spectrum and a large hypochromicity, indicating an intercalating binding mode. This observation was further confirmed by the electrochemical behavior of [(TPP)Co(Trp)] before and after interaction with calf thymus DNA. The complex experiences a negative shift in E _1/2 and a decrease in E _p. The ratio of cathodic to anodic peak currents i _pc/i _pa was 1 for [(TPP)Co(Trp)] while for DNA bound complex i _pc/i _pa 1, suggesting that the calf thymus DNA moiety is bound strongly to the complex [(TPP)Co(Trp)]. Kinetic studies of the DNA-porphyrin complex reveal a psuedo-first order rate law as the plot of k _obs versus calf thymus DNA is linear passing through the origin.     

A ruthenium(II) complex with p‐cymene and (S)‐2‐(anilinomethyl)pyrrolidine

The title compound, [(S)‐2‐(anilino­methyl)­pyrrolidine‐N,N′]‐chloro(η⁶‐para‐cymene)­ruthenium(II) chloride, [RuCl‐(C₁₀H₁₄)(C₁₁H₁₆N₂)]Cl, has been synthesized by the reaction of [RuCl₂(p‐cymene)]₂ (p‐cymene is para‐iso­propyl­toluene) with (S)‐2‐(anilinomethyl)­pyrrolidine in triethyl­amine/2‐propanol. The Ru atom is in a pseudo‐tetrahedral environment coordinated by a chloride ligand, the aromatic hydro­carbon is linked in a η⁶ manner and the amine is linked via its two N atoms. The chloride anion is involved in hydrogen bonding with the di­amine moieties through N—H?Cl interactions, with N?Cl distances of 3.273 (4) and 3.352 (4) Å.     

Structure and catalytic activity of a manganese(III) tetraphenylporpholactone

A manganese(III) complex of tetraphenylporpholactone, Mn(TPPL)Cl, was synthesized and characterized, including by single-crystal X-ray diffraction; the catalytic activity of this complex for olefin epoxidation reactions is compared with that of manganese(III) tetraphenylporphyrin chloride, Mn(TPP)Cl.     

Quantum Chemical Calculation of Conformations and Rotation Barriers of Functional Groups in Arylsulfonyl Halides

The semiempirical PM3 method is used to calculate the potential functions of internal rotation of the functional groups –SO₂Cl, –NO₂, –CH₃, –OCH₃, and –NH₂ of benzenesulfonyl halide molecules (PhSO₂Hal, Hal = F, Cl, Br, I) and twelve substituted derivatives of benzenesulfonyl chloride. Molecular conformations have been determined and internal rotation barriers of the functional groups have been calculated. For meta- and para-substituted benzenesulfonyl chlorides, the projection of the S–Hal bond is perpendicular to the plane of the benzene ring. The rotation barriers of the –SO₂Hal group of benzenesulfonyl halides increase in the series Hal = F, Cl, Br, I. The rotation barriers of the –SO₂Cl group of benzenesulfonyl chloride with meta- and para-substituents slightly increase with the electron-donor properties of the substituent. The rotation barriers of the functional groups of ortho-substituted benzenesulfonyl chlorides are 3 or 4 times as high as those of the meta- and para-isomers. For para-substituted benzenesulfonyl chlorides, the rotation barriers of the functional groups increase in the order –CH₃, –NO₂, –SO₂Cl, –OCH₃, –NH₂.     

Complexation of Ni (II) and Zn(II) ions by 3-(1-naphthyI)-2-mercaptopropenoic acid

The complexation equilibria between Ni(II) and Zn(II) metal ions with 3-(1-naphthyl)-2-mercaptopropenoic acid (H₂NMP) were studied by glass electrode potentiometry, at 25 °C and 1.0 mol·dm^–3 in NaClO₄ as constant ionic medium in 50% (v/v) water-ethanol solutions. Formation constants for the complexes Ni(NMP), Ni(NMP) ₂ ^2– , Zn(NMP) and Zn(NMP) ₂ ^2– , refined by the MINIGLASS program, are reported.     

Metallation of tetradentate N<Subscript>2</Subscript>O<Subscript>2</Subscript> Schiff base with Mn(II), Co(II), Cu(II) and Zn(II): synthesis,characterization and formation constants measurement

Four Schiff base ligands, salabza-H₂ = N,N′-bis(salicylidene)-2-aminobenzylamine, were synthesized by condensation of one mole of 2-aminobenzylamine and two moles of salicylaldehyde and/or two moles of substituted salicylaldehyde (5-OMe, 5-Br, 5-NO₂). All the four Schiff bases and their Mn(II), Co(II), Cu(II) and Zn(II) complexes are characterized by UV-Vis, FT-IR, ¹H NMR spectroscopy, mass spectrometry and elemental analysis. The formation constants and the Gibbs free energies were measured spectrophotometrically for 1:1 complexes in methanol in constant ionic strength (I = 0.1 mol dm⁻³ NaClO₄) and at 25°C. The data refinement was carried out with the SQUAD program. The trend of formation constants of H₂L¹ with M(II) follows the order: Mn(II) (3.97) < Zn(II) (4.30) < Co(II) (4.89) < Cu(II) (5.73)     

Synthesis,characterization, and structural studies of two heteroleptic Mn(II) complexes with tridentate N,N,N-pincer type ligand

Abstract

Molecular and supramolecular structures of two new Mn(II) complexes with tridentate N,N,N-pincer type ligand (L) are presented. [MnL(H₂O)₂Cl]Cl (1) and [MnL(H₂O)₃](NO₃)₂·H₂O (2) have octahedral coordination environments with different degrees of distortion. The molecular packing of 1 and 2 is dominated by strong O–H?Cl and O–H?O H-bonds, respectively, as well as weak C–H?O interactions. The percentage of Cl?H and O?H contacts are 15.5 and 31.5% for 1 and 2, respectively, using Hirshfeld analysis. Based on atoms in molecules theory, the Mn–N, Mn–O, and Mn–Cl bonds have the characteristics of closed shell interactions. Thermal decomposition of L and its Mn(II) complexes are also presented.     

Molecular and ionic complexes of pyrrolidinofullerene bearing chelating 3-pyridyl units

Molecular and ionic complexes of cis-2',5'-di(pyridin-3-yl)pyrrolidino[3',4':1,9](C(60)-I(h))[5,6]fullerene DP3FP with chlorobenzene (C(6)H(5)Cl), manganese(II) tetraphenylporphyrin (Mn(II)TPP) and tetrakis(dimethylamino)ethylene (TDAE) have been obtained for the first time. X-ray single crystal structure determination for the crystalline DP3FP·C(6)H(5)Cl (1) solvate proved unambiguously its molecular structure with the cis-arrangement of chelating 3-pyridyl groups. It has been demonstrated that DP3FP easily forms self-assembled photoactive complexes with metallated porphyrins. For example, the formation of a 1 : 1 complex between DP3FP and zinc (II) tetraphenylporphyrin (Zn(II)TPP) in cyclohexane solution (2) was evidenced using absorption spectroscopy. A successful X-ray single crystal structure determination was performed for a self-assembled triad composed of a DP3FP molecule linked with two Mn(II)TPP molecules in {DP3FP·(Mn(II)TPP)(2)}·(C(6)H(4)Cl(2))(3) (3). A strong organic donor TDAE reduces DP3FP to the radical anion state thus forming an ionic complex (TDAE˙(+))·(DP3FP˙(-))·(C(6)H(4)Cl(2))(1.6) (4). Optical, electronic and magnetic properties of 4 were investigated in detail. The performed studies strongly suggest that pyrrolidinofullerene DP3FP can be used as a building block in the design of various organic materials with advanced optoelectronic and/or magnetic properties.     

Manganese Complexes with Octaphenyltetraazaporphine: Acid–Base Interactions and Kinetic Stability in Proton-Donor Solvents

Complexes of manganese(III) and manganese(V) with octaphenyltetraazaporphine (H₂OPTAP) were synthesized. Acid–base interactions of these complexes in the CH₂Cl₂–CF₃COOH system and kinetics of their dissociation in concentrated sulfuric acid, as well as kinetics of octaphenyltetraazaporphine destruction in sulfuric acid solutions were studied by spectrophotometric methods. Acid–base interactions in CH₂Cl₂–CF₃COOH were shown to involve two macrocyclic meso-nitrogen atoms in succession. Concentration stability constants of the acid forms obtained pK ₁ = 0.29 ± 0.01 and pK ₂ = –0.62 ± 0.08 for (chlorine)manganese(III)octaphenyltetraazaporphine ((Cl)MnOPTAP); pK ₁ = 0.99 ± 0.02 and pK ₂ = – 0.70 ± 0.03 for (nitrido)manganese(V)octaphenyltetraazaporphine ((N)MnOPTAP). The rate of dissociation of the complexes in 94–98% H₂SO₄ does not depend on the acid concentration. The manganese(V) complex is three times as stable as the manganese(III) complex.     

Ethylenediamine complexes of transition metalbis(chlorosulphates)

Summary The number and positions of the i.r. active modes in ethylenediamine complexes of M(SO₃Cl)₂ (M = Mn, Fe, Co, Ni or Cu) suggest that the SO₃Cl^– anion is covalently bound in these non-electrolytic complexes. Magnetic moments and ligand field data suggest that each SO₃Cl^– group is monodentate, giving an octahedral geometry around the metal ions.