5,15-二(对-取代苯基)八烷基卟啉及其金属配合物的合成

本文报道了五种5,15-二(对-取代苯基)-2,8,12,18-四乙基-3,7,13,17-四甲基卟啉(Ⅱa—Ⅱe)和五种5,15-二(对-取代苯基)-2,3,7,8,12,13,17,18-八甲基卟啉(Ⅰa—Ⅰe)以及它们的铜、铁、镍金属配合物的合成。这些化合物的结构均经元素分析、UV、~1HNMR和MS鉴定。芳环上不同取代基对卟啉成环反应有一定影响,拉电子基团有利于反应。其顺序如下:NO_2>H>CH_3>OCH_3>N(CH_3)_2。     

Meso-porphyrinylphosphine oxides: mono- and bidentate ligands for supramolecular chemistry and the crystal structures of monomeric {[10,20-diphenylporphyrinatonickel(II)-5,15-diyl]-bis-[P(O)Ph(2)] and polymeric self-coordinated {[10,20-diphenylporphyrinatozinc(II)-5,15-diyl]-bis-[P(O)Ph(2)]}

A series of porphyrins substituted in one or two meso positions by diphenylphosphine oxide groups has been prepared by the palladium-catalyzed reaction of diphenylphosphine or its oxide with the corresponding bromoporphyrins. Compounds {MDPP-[P(O)Ph2]n} (M = H2, Ni, Zn; H2DPP = 5,15-diphenylporphyrin; n = 1, 2) were isolated in yields of 60-95%. The reaction is believed to proceed via the conventional oxidative addition, phosphination, and reductive elimination steps, as the stoichiometric reaction of eta(1)-palladio(II) porphyrin [PdBr(H2DPP)(dppe)] (H2DPP = 5,15-diphenylporphyrin; dppe = 1,2-bis(diphenylphosphino)ethane) with diphenylphosphine oxide also results in the desired mono-porphyrinylphosphine oxide [H2DPP-P(O)Ph2]. Attempts to isolate the tertiary phosphines failed due to their extreme air-sensitivity. Variable-temperature 1H NMR studies of [H2DPP-P(O)Ph2] revealed an intrinsic lack of symmetry, while fluorescence spectroscopy showed that the phosphine oxide group does not behave as a "heavy atom" quencher. The electron-withdrawing effect of the phosphine oxide group was confirmed by voltammetry. The ligands were characterized by multinuclear NMR and UV-visible spectroscopy, as well as mass spectrometry. Single-crystal X-ray crystallography showed that the bis(phosphine oxide) nickel(II) complex {[NiDPP-[P(O)Ph2]2} is monomeric in the solid state, with a ruffled porphyrin core and the two P=O fragments on the same side of the average plane of the molecule. On the other hand, the corresponding zinc(II) complex formed infinite chains through coordination of one Ph2PO substituent to the neighboring zinc porphyrin through an almost linear P=O...Zn unit, leaving the other Ph2PO group facing into a parallel channel filled with disordered water molecules. These new phosphine oxides are attractive ligands for supramolecular porphyrin chemistry.     

Syntheses, structures, and properties of tetrakis(mu-acetato)dirhodium(II) complexes with axial pyridine nitrogen donor ligands with or without assistance of hydrogen bonds

Eight adducts of Rh2(O2CCH3)4 with axial pyridine derivatives that contain hydrogen-bonding amino and/or steric methyl substituents in the 2- and 6-positions have been prepared and examined by electronic absorption and 1H NMR spectroscopy in solution and by elemental, IR, thermogravimetric, and X-ray diffraction analyses in the solid state. The results indicated that strong hydrogen bonding interactions between Rh2(O2CCH3)4 and axially coordinated pyridine derivatives with a 2- or 6-amino group occur in both solution and the solid state and contribute to the higher thermal stability of the molecular assembly of dirhodium complexes. It was demonstrated that such a combination of coordinate and hydrogen bonds is useful as a building tool in designing and constructing new organic-inorganic hybridized compounds and supramolecular architectures.     

Supramolecular ensembles based on the donor-acceptor interactions of porphyrins

Dimeric and trimeric supramolecular structures were synthesized on the basis of donor-acceptor interactions of manganese(III) and tin(IV) complexes of 5,15-diphenyl-3,7,13,17-tetramethyl-2,8,12,18-tetrabutylporphyrin with 5-(4′-oxyphenyl)-15-phenyl-3,7,13,17-tetramethyl-2,8,12,18-tetrabutylporphyrin. The structure of the compounds was studied by NMR spectroscopy and TLC.     

Synthesis of mono- and disubstituted porphyrins: A- and 5,10-A2-type systems

General syntheses have been developed for meso-substituted porphyrins with one or two substituents in the 5,10-positions and no beta substituents. 5-Substituted porphyrins with only one meso substituent are easily prepared by an acid-catalyzed condensation of dipyrromethane, pyrrole-2-carbaldehyde, and an appropriate aldehyde using a "[2+1+1]" approach. Similarly, 5,10-disubstituted porphyrins are accessible by simple condensation of unsubstituted tripyrrane with pyrrole and various aldehydes using a "[3+1]" approach. The yields for these reactions are low to moderate and additional formation of either di- or monosubstituted porphyrins due to scrambling of the intermediates is observed. However, the reactions can be performed quite easily and the desired target compounds are easily removed due to large differences in solubility. A complementary and more selective synthesis involves the use of organolithium reagents for S(N)Ar reactions. Reaction of in situ generated porphyrin (porphine) with 1.1-8 equivalents of RLi gave the monosubstituted porphyrins, while reaction with 3-6 equivalents of RLi gave the 5,10-disubstituted porphyrins in yields ranging from 43 to 90 %. These hitherto almost inaccessible compounds complete the series of different homologues of A-, 5,15-A(2)-, 5,10-A(2)-, A(3)-, and A(4)-type porphyrins and allow an investigation of the gradual influence of type, number, and regiochemical arrangement of substituents on the properties of meso-substituted porphyrins. They also present important starting materials for the synthesis of ABCD porphyrins and are potential synthons for supramolecular materials requiring specific substituent orientations.     

Ion‐Pairing Assemblies of Porphyrin–AuIII Complexes in Combination with π‐Electronic Receptor–Anion Complexes

Anion complexes of anion‐responsive π‐electronic molecules can behave as pseudo π‐electronic anions providing various ion pairs in combination with countercations. In this study, single crystals of ion‐pairing assemblies comprising porphyrin–Au^III complexes and Cl^? complexes of dipyrrolyldiketone BF₂ complexes were prepared from 1:1 mixtures of anion receptors and the Cl^? salts of cationic porphyrins in solution. In the solid state, the ion pairs formed characteristic assemblies, depending on the substituents of the anion receptors and porphyrin–Au^III complexes. Theoretical calculations on the ion pairs revealed that the stacking structures are stabilized by compensating positive and negative charges as well as π–π interactions.     

Noncovalent binding between fullerenes and protonated porphyrins in the gas phase

Noncovalent interactions between protonated porphyrin and fullerenes (C?? and C??) were studied with five different meso-substituted porphyrins in the gas phase. The protonated porphyrin-fullerene complexes were generated by electrospray ionization of the porphyrin-fullerene mixture in 3:1 dichloromethane/methanol containing formic acid. All singly protonated porphyrins formed the 1:1 complexes, whereas porphyrins doubly protonated on the porphine center yielded no complexes. The complex ion was mass-selected and then characterized by collision-induced dissociation with Xe. Collisional activation exclusively led to a loss of neutral fullerene, indicating noncovalent binding of fullerene to protonated porphyrin. In addition, the dissociation yield was measured as a function of collision energy, and the energy inducing 50% dissociation was determined as a measure of binding energy. Experimental results show that C?? binds to the protonated porphyrins more strongly than C??, and electron-donating substituents at the meso positions increase the fullerene binding energy, whereas electron-withdrawing substituents decrease it. To gain insight into π-π interactions between protonated porphyrin and fullerene, we calculated the proton affinity and HOMO and LUMO energies of porphyrin using Hartree-Fock and configuration interaction singles theory and obtained the binding energy of the protonated porphyrin-fullerene complex using density functional theory. Theory suggests that the protonated porphyrin-fullerene complex is stabilized by π-π interactions where the protonated porphyrin accepts π-electrons from fullerene, and porphyrins carrying bulky substituents prefer the end-on binding of C?? due to the steric hindrance, whereas those carrying less-bulky substituents favor the side-on binding of C??.     

Synthesis of Metal Porphyrins Tailed with Salicylic Acid and their Interaction with Bovine Serum Albumin

A synthetic method of porphyrins tailed with salicylic substituents is described.Reaction of bromoalkoxyphenyl porphyrin 1 with salicylic acid gave porphyrins 2-5. These new compounds were confirmed by ^1H NMR, IR, UV-vis, MS and elemental analysis, and observed their interaction with bovine serum albumin (BSA) in fluorescence spectrum.     

Assembly behavior of inclusion complexes of beta-cyclodextrin with 4-hydroxyazobenzene and 4-aminoazobenzene

To further reveal the factors governing the supramolecular assembly of beta-cyclodextrin (beta-CD) inclusion complexes, two aggregates (1 and 2) were prepared from the inclusion complexes of beta-CD with 4-hydroxyazobenzene and 4-aminoazobenzene, respectively, and their binding behavior were investigated by means of X-ray analysis, UV-vis, NMR, and circular dichroism spectra in both solution and the solid state. The obtained results indicated that the beta-CD/4-hydroxyazobenzene complex 1 could form head-to-head dimers (triclinic system, space group P1) in the solid state, which were further self-assembled to a linear supramolecular architecture by the intra- and interdimer hydrogen bond interactions as well as the intradimer pi-pi interactions. However, when the included guest 4-hydroxyazobenzene was switched to a 4-aminoazobenzene, the resultant beta-CD/4-aminoazobenzene complex 2 (monoclinic system, space group P2(1)) could be self-assembled to a wave-type supramolecular aggregate under similar conditions. Furthermore, the combination of crystallographic and spectral investigations jointly revealed the inclusion complexation geometry of beta-CD with 4-hydroxyazobenzene and 4-aminoazobenzene in both solution and the solid state, which demonstrated that the disparity of substituents in the azobenzenes played an important role in the inclusion complexation and molecular assembly, affecting not only the structural features of aggregates but also the binding abilities of azobenzenes with beta-CD.     

Structures and ligand exchange of N-confused porphyrin dimer complexes with group 12 metals

N-confused 5,20-diphenylporphyrin (NCDPP, 1) formed 2:2 dimer complexes with group 12 metals both in the solid state and in solution. X-ray single-crystal analyses of the Zn(II) and Cd(II) complexes (7, 8) revealed that each metal ion is coordinated with three inner core nitrogens and a peripheral nitrogen of the other NCDPP in the pair. In the (1)H NMR spectra of 7, 8, and the Hg(II) complex (9), the outer alpha-H signals of the confused pyrrole ring appeared in the upfield region at 2.57, 3.44, and 3.60 ppm, respectively, due to the ring current effect by the coordinated porphyrins. In the case of the Cd(II) and Hg(II) complexes (8, 9), additional magnetic couplings with the metal nuclei of the partner rings were observed. The equilibrium constants (K) of the monomer exchange reaction at 25 degrees C were determined to be 2.5, 1.3, and 0.6 for the (Zn-Cd), (Cd-Hg), and (Zn-Hg) heterodimer complexes, respectively, from the (1)H NMR spectra of a solution containing two different dimers. Furthermore, a metal-transfer reaction from a Zn(II) NCP dimer complex to the free base porphyrin was demonstrated.     

卟啉类L-B膜分子间相互作用的光谱研究

以无取代的meso-四-(4-N)-吡啶基卟啉及其过渡族金属(主要Cu~(2+)、Zn~(2+))络合物制备L-B膜,以近紫外-可见吸收光谱和荧光光谱为手段,研究叶啉类分子在氯仿溶液中,L-B膜状态下以及固态状态下的相互作用。探讨分子聚集体的存在对光谱性质的影响。 为了研究叶咻类分子间的相互作用及其对光谱性质的影响,我们首先分析了叶啉在CHCl_3溶液中及固态状态下的近紫外-可见吸收光谱和荧光光谱。并将其与叶啉类分子的L-B膜作比较。结果表明,卟啉类的Soret吸收带带宽及峰位置在三种状态下均不相同,L-B膜的情况介于溶液中的和固体下的情况之间,说明了在L-B膜中,卟啉分子存在着某种形式的聚集体,且在这种聚集体中分子间的相互作用程度比固体弱,可以认为L-B膜上的分子呈准晶体状态。     

Synthesis of Covalently-linked Linear Donor-Acceptor Copolymers Containing Porphyrins and Oligothiophenes

The construction of macro-molecular system containing multiple redox centers or photosensitizers is aimportant subject in the design of molecular electronidevices.1,2 For such objectives, systematization of donor-redox center-acceptor triad molecules into largmolecular systems is one of the most feasible approaches, because the exquisite incorporation of thphotosensitizers and suitable electron donors and/oacceptors into a polymeric chain is useful for varioumolecular electronic systems.3-5 Th…     

Recognition through self-assembly. A quadruply-hydrogen-bonded, strapped porphyrin cleft that binds dipyridyl molecules and a [2]rotaxane

Quadruply-hydrogen-bonded porphyrin homodimer Zn1.Zn1 has been designed, assembled, and evaluated as a supramolecular cleft-featured receptor for its ability to bind dipyridyl guests in chloroform-d. Monomer Zn1 consists of a 2-ureidopyrimidin-4(1H)-one unit, which was initially reported by Meijer et al., and a zinc porphyrin unit. The zinc porphyrin is strapped with an additional aliphatic chain for controlling the atropisomerization of porphyrin. The 2-ureidopyrimidin-4(1H)-one unit dimerizes exclusively in chloroform even at the dilute concentration of 10(-)(4) M, while the two "strapped" zinc porphyrin units of the homodimer provide additional binding sites for selective guest recognition. (1)H NMR studies indicate that the new homodimer Zn1.Zn1 adopts an S-type conformation due to strong donor-acceptor interaction between the electron-rich porphyrin units and the electron-deficient 2-ureidopyrimidin-4(1H)-one unit. (1)H NMR, UV-vis, and vapor pressure osmometry investigations reveal that Zn1.Zn1 could function as a new generation of assembled supramolecular cleft, to be able to not only efficiently bind linear dipyridyl molecules 14-17, resulting in the formation of stable termolecular complexes, with K(aasoc) values ranging from 3.8 x 10(6) to 8.9 x 10(7) M(-)(1), but also strongly complex a hydrogen-bond-assembled [2]rotaxane, 18, which consists of a rigid fumaramide thread and a pyridine-incorporated tetraamide cyclophane, with K(aasoc) = 1.2 x 10(4) M(-)(1). (1)H NMR competition experiments reveal that complexation to the dipyriyl guests also promotes the stability of the quadruply-hydrogen-bonded dimeric receptor.     

3-Cyclobutenyl-1,2-dione-substituted porphyrins. A general and efficient entry to porphyrin-quinone and quinone-porphyrin-quinone architectures

A new and efficient synthesis of meso-linked porphyrin-quinone dyads and quinone-porphyrin-quinone triads has been developed via the intermediacy of porphyrins bearing 3-cyclobutenyl-1,2-dione and 3-(1-ethenyl)cyclobutenyl-1,2-dione substituents at one or two nonadjacent meso-positions. The free-base porphyrins 5-bromo-10,20-diphenylporphyrin and 5,15-dibromo-10,20-diphenylporphyrin undergo facile palladium-catalyzed Stille coupling with 3-isopropoxy-2-tri-n-butylstannyl-cyclobutene-1,2-dione to produce the corresponding mono- and bis(3-cyclobutenyl-1,2-dione)-substituted porphyrins in good yields. In contrast, the zinc bromoporphyrins reacted with the same tin reagent only slowly and with the formation of side products. The free-base bromoporphyrins also were coupled with tri-n-butylvinyltin to afford vinylporphyrins in very good yields. 5,15-Diphenyl-10-vinylporphyrin was converted into trans-bromovinylporphyrin, which underwent facile Stille coupling with 3-isopropoxy-2-tri-n-butylstannylcyclobutene-1,2-dione to afford the vinylogous 3-cyclobutenyl-1,2-dione-substituted porphyrin. The molecular structure of 5,15-bis(3-cyclobutenyl-1,2-dione)-10,20-diphenylporphyrin(Z n) was determined by X-ray crystallography. Although the data revealed a fairly large dihedral angle between the cyclobutenedione and the porphyrin rings (57 degrees), the UV-vis spectra of both the mono- and bis(3-cyclobutenyl-1,2-dione)-substituted porphyrins showed B- and Q-band red shifts indicative of strong electronic coupling between the porphyrin and cyclobutenedione chromophores in solution. Introduction of a double bond between the cyclobutenedione and porphyrin rings resulted in a significant red shift of both the B- and Q-bands compared to those of the nonvinylogous system. All porphyrinic cyclobutenediones were metalated with zinc and then, using established cyclobutenedione chemistry, converted into a variety of porphyrin-quinones in excellent yields with aryllithium and vinylic Grignard reagents. From the mono(3-cyclobutenyl-1,2-dione)-substituted porphyrin, 7, a variety of directly linked monoquinone-porphyrin dyads were easily synthesized. Substituents could also be introduced at the free meso-position of 7 by bromination followed by palladium-catalyzed cross-coupling reactions, and additional porphyrinic monoquinones were then prepared from these starting materials. The vinylogous squarylporphyrin was converted into a double bond linked porphyrin-quinone via reaction with phenyllithium followed by thermal rearrangement and oxidation. As a result of the hindered rotation around the C-C bond between the porphyrin and the quinone, pairs of stable, separable, and thermally interconvertable atropisomers of porphyrin-quinones were obtained from 5,15-bis(3-cyclobutenyl-1,2-dione)-10,20-diphenylporphyrin(Z n). The structure of one of the atropisomers was determined by X-ray crystallography.     

Synthesis of porphyrins bearing uracyl groups and their assembly induced by melamine derivatives

Self‐assembled porphyrins via noncovalent bonding have attracted wide‐ranging researchers in material science. We reported herein the synthesis of the tetraphenyl porphyrin derivatives bearing uracyl groups as acceptor–donor–acceptor (ADA) type hydrogen bonding units, through the condensation of 5,10‐ or 5,15‐bis (3‐amino‐4‐ethylhexylphenyl) porphyrin derivatives with 6‐carboxyuracyl derivatives. When two porphyrins having uracyl groups at the different substituted positions were respectively mixed with a melamine derivative in benzene, ¹H NMR spectra showed that the 5,15 substituted uracyl porphyrin formed a hydrogen‐bonded suprastructure with the melamine derivative as a complementary molecule to the uracyl moiety, although the other 5,10‐substituted uracylporphyrin could not form such a structure. The SEM observation indicated that the mixture with the 5,15‐substituted uracyl porphyrin and the melamine with long alkyl chains formed a sheet‐like structure. Copyright © 2007 John Wiley & Sons, Ltd.     

Rh(III) porphyrins as building blocks for porphyrin coordination arrays: from dimers to heterometallic undecamers

The coordination chemistry of a Rh(III) porphyrin building block was investigated with a view to the construction of heterometallic arrays of porphyrins. The Rh(III) porphyrin was found to coordinate methanol in the solid state and weakly in CDCl(3) solution. Crystallization afforded five coordinate pi stacked Rh(III) porphyrins. The distribution of products from reaction of Rh(III) porphyrin with DABCO, 4,4'-bipyridine, and 4,4'-bipyrimidine could be displaced toward dimeric species by silica gel column chromatography or recrystallization which served to remove excess ligand. Weak coordination to nitriles was observed, although it was sufficiently strong to organize a dimeric complex of 5,5'-dicyano-2,2'-bipyridine in the solid state. Complexes with 4,4'-bipyrimidine and 5,5'-dicyano-2,2'-bipyridine possess uncoordinated chelating nitrogen atoms. Larger heterometallic porphyrin arrays were assembled using a combination of Sn(IV) and Rh(III) porphyrin coordination chemistry. A Sn(IV) porphyrin acted as a core around which were coordinated two isonicotinate groups, carboxylic acid functionalized porphyrins, or porphyrin trimer dendrons. Rh(III) porphyrins were coordinated to pyridyl groups at the periphery of these entities. In this way an eleven porphyrin array, with four different porphyrin metalation states, was assembled. The diamagnetic nature of both the Rh(III) and Sn(IV) porphyrins, the slow ligand exchange kinetics on the NMR time scale, and tight ligand binding permitted the porphyrin arrays to be analyzed by two-dimensional (1)H NMR techniques.     

Synthesis and conformational studies of chiral meso-(α,β-unsaturated)-porphyrins

We describe a method to improve the yield and the kinetics of the difficult syntheses of α,β-unsaturated porphyrins, which enabled us to obtain a new chiral porphyrin derived from (S)-(−)-perillaldehyde in a 6% yield. Variable temperature NMR experiments on the free base, the zinc(II) and the nickel(II) complexes showed that two distinct and consecutive dynamic processes linked with the meso substituents rotation occurred. These processes can be analyzed as an evolution of the conformer composition upon temperature change. Higher values are found for the free energies of rotation of the substituent (measured by variable temperature ¹H NMR) compared to those of other equivalent porphyrins like meso-tetraphenyl porphyrin or meso-tetracyclohexyl porphyrin.     

水杨酸键联卟啉的合成及与牛血清白蛋白的相互作用

以溴代烷氧基苯基卟啉(1)为原料与水杨酸作用,分别得到了化合物2和3,再与醋酸钴反应,得到了钴卟啉配合物4和5.新化合物分别由¹HNMR,IR,UV-Vis,MS和元素分析确证.同时,利用荧光光谱考察了金属卟啉与牛血清白蛋白的相互作用.     

Giant Shape-Persistent Tetrahedral Porphyrin System: Light-Induced Charge Separation

Tetraphenylmethane appended with four pyridylpyridinium units works as a scaffold to self-assemble four ruthenium porphyrins in a tetrahedral shape-persistent giant architecture. The resulting supramolecular structure has been characterised in the solid state by X-ray single crystal analysis and in solution by various techniques. Multinuclear NMR spectroscopy confirms the 1 : 4 stoichiometry with the formation of a highly symmetric structure. The self-assembly process can be monitored by changes of the redox potentials, as well as by modifications in the visible absorption spectrum of the ruthenium porphyrin and by a complete quenching of both the bright fluorescence of the tetracationic scaffold and the weak phosphorescence of the ruthenium porphyrin. An ultrafast photoinduced electron transfer is responsible for this quenching process. The lifetime of the resulting charge separated state (800 ps) is about four times longer in the giant supramolecular structure compared to the model 1 : 1 complex formed by the ruthenium porphyrin and a single pyridylpyridinium unit. Electron delocalization over the tetrameric pyridinium structure is likely to be responsible for this effect.     

Triplet photophysics of gold(III) porphyrins

Gold porphyrins are often used as electron-accepting chromophores in donor-acceptor complexes for the study of photoinduced electron transfer, and they can also be involved in triplet-triplet energy-transfer interactions with other chromophores. Since the lowest excited singlet state is very short-lived (240 fs), the triplet state is usually the starting point for the transfer reactions, and it is therefore crucial to understand its photophysics. The triplet state of various gold porphyrins has been reported to have a lifetime of around 1.5 ns at room temperature and to have a biexponential decay both in emission and in transient absorption with decay times of around 10 and 100 micros at 80 K. In this paper, the triplet photophysics of two gold porphyrins (Au(III) 5,15-bis(3,5-di-tert-butylphenyl)-2,8,12,18-tetraethyl-3,7,13,17-tetramethylporphyrin and Au(III) 5,10,15,20-tetra(3,5-di-tert-butylphenyl)porphyrin) are studied by steady-state and time-resolved absorption and emission spectroscopy over a wide temperature range (4-300 K). The study reveals the existence of a dark state with an approximate lifetime of 50 ns, which was not previously observed. This state acts as an intermediate between the short-lived singlet and the triplet state manifold. In addition, we present DFT calculations, in which the core electrons of the central metal were replaced by a pseudopotential to account for the relativistic effects, which suggest that the lowest excited singlet state is an optically forbidden ligand-to-metal charge-transfer (LMCT) state. This LMCT state is an obvious candidate for the experimentally observed dark state, and it is shown to dictate the photophysical properties of gold porphyrins by acting as a gate for triplet state formation versus direct return to the ground state.