Formation and stability of gaseous tolyl ions

Collisional activation mass spectra confirm that tolyl ions can be produced from a variety of CH₃C₆H₄Y compounds. High purity o-, m- and p-tolyl ions are prepared by chemical ionization of the corresponding fluorides (Y=F) as proposed by Harrison. In electron ionization of CH₃C₆H₄Y formation of the more stable tropylium and benzyl ionic isomers usually accompanies that of the o-, m- and p-tolyl ions. Isomerization of low energy [CH₃C₆H₄Y]⁺? to [Y–methylenecyclohexadiene]⁺? is proposed to account for most [benzyl]⁺ formation, while the tropylium ion appears to arise from the isomerization of tolyl ions formed with higher internal energies, [o-, m-, p-tolyl]⁺→ [benzyl]⁺→ [tropylium]⁺, consistent with Dewar's predictions from MINDO/3 calculations.     

Theoretical studies on the structure and protonation of Cu(II) complexes of a series of tripodal aliphatic tetraamines: Good correlations with the experimental data

DFT(B3LYP) studies on first protonation step of a series of Cu(II) complexes of some tripodal tetraamines with general formula N[(CH₂)_nNH₂][(CH₂)_mNH₂][(CH₂)_pNH₂] (n = m = p = 2, tren; n = 3, m = p = 2, pee; n = m = 3, p = 2, ppe; n = m = 3, tpt; n = 2, m = 3, p = 4, epb; and n = m = 3, p = 4; ppb) are reported. First, the gas‐phase proton macroaffinity of all latter complexes was calculated with considering following simple reaction: [Cu(L)]²⁺(g) + H⁺(g) → [Cu(HL)]³⁺(g). The results showed that there is a good correlation between the calculated proton macroaffinities of all complexes with their stability constants in solution. Then, we tried to determine the possible reliable structures for microspecies involved in protonation process of above complexes. The results showed that, similar to the solid state, the [Cu(L)(H₂O)]²⁺ and [Cu(HL)(H₂O)₂]³⁺ are most stable species for latter complexes and their protonated form, respectively, at gas phase. We found that there are acceptable correlations between the formation constants of above complexes with both the ? and ? of following reaction: [Cu(L)(H₂O)]²⁺(g) + H⁺(g) + H₂O(g) → [Cu(HL)(H₂O)₂]³⁺(g). The ? of the latter reaction can be defined as a theoretically solvent–proton macroaffinity of reactant complexes because they have gained one proton and one molecule of the solvent. The unknown formation constant of [Cu(epb)]²⁺ complex was also predicted from the observed correlations. In addition, the first proton affinity of all complexes was studied in solution using DPCM and CPCM methods. It was shown that there is an acceptable correlation between the solvent–proton affinities of [Cu(L)(H₂O)]²⁺ complexes with formation constants of [Cu(HL)(H₂O)₂]³⁺ complexes in solution. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010     

Metastable ion and induced stable ion fragmentation of isomeric 5-methyl-3-tolyl-1,2,4-oxadiazoles

The electron ionization fragmentation patterns of 5-methyl-3-(o-, m- and p-tolyl)-1,2,4-oxadiazoles (1a—c) have been examined by metastable ion and high resolution mass spectrometry. The o-tolyl isomer loses CO and C₂H₂O from the metastable molecular ion whereas the m- and p-tolyl isomers lose only CH₃CN thus indicating a strong ortho effect in directing the fragmentation in 1a. Slight differences between o-, m- and p-tolyl isomers in the collisional activation fragmentation of stable [C₇H₆N]⁺ ions suggest that structural differences exist even after a series of extensive rearrangements of the molecular ions. Metastable ion kinetic energy (MIKE) and collisional activation (CA) spectra were very helpful in providing valuable information about many fragments.     

Synthesis of porphyrinyl-nucleosides

Several porphyrinyl-nucleosides were prepared in the reaction of the OH group of one, two or four meso-p-hydroxyphenyl substituents of porphyrin with 5′-O-tosylates of 2′,3′-O-isopropylidene-adenosine or -uridine, or 5′-O-tosylthymidine; the remaining porphyrin meso-substituents were p-tolyl, p-hydroxyphenyl or 4-pyridyl. The following porphyrinyl-nucleosides were obtained with 8–17% yield: meso-di(p-tolyl)di(p-phenylene-5′-O-2′,3′-O-isopropylidene-adenosine) (or -uridine)porphyrins 1,2 , the respective meso-tetranucleosideporphyrins 3,4 -meso-mono(p-phenylene-5′-O-thymidine)porphyrins 5–7 , meso-di(p-tolyl)di(p-phenylene-5′-O-thymidine)porphyrins 8,9 and the meso-di(p-hydroxyphenyl)di(p-phenylene-5′-O-thymidine)porphyrins 10. Other compounds prepared belonged to the series: meso(4-pyridyl)_4?n(p-phenylene-5′-O-2′,3′-O-isopropylideneuridine)_nporphyrin, n = 1, 2 or 4, 11–13. N-Methylation gave the water soluble iodide salts: (N-methyl-4-pyridinium)4_4?n(p-phenylene-5′-O-2′,3′-isopropylideneuridine)_nporphyrins, n = 1, 2 or 4, 14–16. The ms fab showed in most cases stepwise detachment of the CH₂(5′)-nucleoside fragments. The porphyrins meso disubstituted by thymidine represent a convenient substrate for the build-up of both nucleoside units into the oligo/polynucleotide chains.     

Electron impact ionization of ethylene–methanol heteroclusters: Stable configurations and mechanisms in intracluster ion–molecule reactions

Reactions that proceed within mixed ethylene–methanol cluster ions were studied using an electron impact time-of-flight mass spectrometer. The ion abundance ratio, [(C₂H₄)_n(CH₃OH)_mH⁺]/[(C₂H₄)_n(CH₃OH)_m⁺], shows a propensity to increase as the ethylene/methanol mixing ratio increases, indicating that the proton is preferentially bound to a methanol molecule in the heterocluster ions. The results from isotope-labelling experiments indicate that the effective formation of a protonated heterocluster is responsible for ethylene molecules in the clusters. The observed (C₂H₄)_n(CH₃OH)_m⁺ and (C₂H₄)_n(CH₃OH)_m–1CH₃O⁺ ions are interpreted as a consequence of the ion–neutral complex and intracluster ion–molecule reaction, respectively. Experimental evidence for the stable configurations of heterocluster species is found from the distinct abundance distributions of these ions and also from the observation of fragment peaks in the mass spectra. Investigations on the relative cluster ion distribution under various conditions suggest that (C₂H₄)_n(CH₃OH)_mH⁺ ions with n + m ≤ 3 have particularly stable structures. The result is understood on the basis of ion–molecule condensation reactions, leading to the formation of fragment ions, $ {\rm CH}_2=\!=\mathop {\rm O}\limits^ + {\rm CH}_3 $ and (CH₃OH)H₃O⁺, and the effective stabilization by a polar molecule. The reaction energies of proposed mechanisms are presented for (C₂H₄)_n(CH₃OH)_mH⁺(n + m ≤ 3) using semi-empirical molecular orbital calculations.     

Energetics of proton transfer between carbon atoms (H3CH ? CH3)−

Ab initio calculations were carried out to study the potential energy surface of (H₃C? H? CH₃)^?. The 6–31G* basis set is supplemented by a set of diffuse p functions on both C and H (with a range of exponents for the latter). The binding energy of CH₄ and CH₃^? to form the (H₃CH? CH₃)^? complex is about 2 kcal/mol, much smaller than for comparable ionic H-bonded systems involving O or N atoms. Nearly half of this interaction energy is due to correlation effects, computed at second and third orders of Møller-Plesset perturbation theory. Correlation is also responsible for substantial reductions in the energy barrier to proton transfer within the complex. This barrier is computed to be 13?15 kcal/mol at the MP3 level, depending upon the exponent used for the H p functions.     

Polyamides from α,ω-oxaalkanedioic acids having long methylene chain units

Three series of polyamides were prepared from diamines (hexamethylenediamine, bis-5-aminoamyl ether, p-xylylenediamine) and α,ω-oxaalkanedioic acids of formula HOOC(CH₂)_mO(CH₂)_nCOOH, where m = n = 3–10, in symmetric structures, but m = 3 or 4 in unsymmetric structures. The melting points of these polymers were plotted against the number of carbon atoms of the oxaalkylene groups. The melting points of polymers from each diamine fell on three different curves according to the structures of the dicarboxylic acids: symmetric ? (CH₂)_nO(CH₂)_n? ; unsymmetric ? (CH₂)₃O(CH₂)_n? , and unsymmetric ? (CH₂)₄O(CH₂)_n? . A minimum melting point is observed at about the same point of the acid structure in every curve of the unsymmetric dicarboxylic acids. The marked depression in the polymer melting points around the minimum point is attributed to the increase of the entropy of fusion.     

Polymerization of acrylonitrile by catalytic systems consisting of triphenylphosphine and a lewis acid

Polymerization of acrylonitrile in the presence of systems that consisted of triphenylphosphine (PPh₃) and a Lewis acid R_mMX_n (ZnCl₂, Me₃Al, Et₃Al, Et₂AlCl, EtAlCl₂, AlCl₃) was studied. The systems that contained Me₃Al and Et₃Al (i.e., Lewis acid of moderate acidity) were the most efficient catalysts. Conductometric measurements carried out in the polymerization systems showed the presence of ions. The presence of phosphonium cation in the polyacrylonitrile chain formed by the PPh₃–R_mMX_n catalytic systems was determined by IR, ¹H-NMR, and ³¹P-NMR spectroscopy. The average molecular weight measurements and kinetic chain lengths of polyacrylonitrile formed within the reaction time in the presence of PPh₃–Et₃Al showed that transfer reactions occur. According to the results obtained, the polymerization reaction of acrylonitrile by PPh₃–R_mMX_n involved a zwitterion formed by the attack of PPh₃ on acrylonitrile complexed by Lewis acid [Ph₃P^⊕? CH₂? C^?H? C?N → MR_mX_n] and the anion [CH₂?C^?? C?N] formed by the proton abstraction from the monomer.     

Zum basenkatalysierten H/D-Austausch des acetylenischen Wasserstoffatoms in aromatischen Alkinylverbindungen

On the Base-Catalysed H/D-Exchange of the Acetylenic Hydrogen Atom in Aromatic Alkynyl Compounds H/D-exchange rates for a number of compounds of the general type 1 (X = p-CH₃O, m-CH₃O, p-CF₃, m-CF₃, p-CH₃, p-Cl, H; Z ? O, NH, CH₂) were determined in N-methyl-pyrrolidine (NMP)/D₂O mixtures at 25° (see Table 1). It is shown that the log k values of the H/D-exchange correlate nicely (r = 0.995) with the chemical shift of the acetylenic proton in 1 . Thus, the H/D-exchange rate is given by log k (min^?1) = 2.91 · δ (ppm) - 7.79 for the NMP/D₂O mixture at 25°.     

Zur Photochemie von 3,5-Diaryl-2-isoxazolinen. 30. Mitteilung über Photoreaktionen

Irradiation of 3,5-diphenyl- or 3-(p-tolyl)-5-phenyl-2-isoxazoline ( 12 and 13 , respectively) in benzene with a high-pressure mercury lamp yields 4,5-diphenyl- or 4-(p-tolyl)-5-phenyl-3-oxazoline ( 17 and 19 , respectively) and the β-amino-chalcones 18 or 20 in addition to benzaldehyde, benzonitrile and p-tolunitrile, respectively (scheme 6 and ‘Anmerkg.’ p. 2600). The 3-oxazolines 17 and 19 are formed by route a (scheme 8) via 3-phenyl- or 3-(p-tolyl)-2H-azirine ( 23 , R = H and CH₃, respectively) and their photochemically rearranged successors, the nitrile methylides 24 , as intermediates. The discovery of this reaction has served as a basis for the quickly developing photochemistry of 3-aryl-2H-azirines [2] [24]. Photolysis of the 2-isoxazoline 13 in methanol leads to the formation of a mixture of syn/anti-p-tolyl trans-styryl ketoximes (syn/anti, trans- 30 ) and anti, cis- 30 , 2-(p-tolyl)-quinoline ( 29 ), the 4-hydroxymethylated derivative 32 of the latter (in small amounts), besides the β-aminochalcone 20 , benzaldehyde, p-tolualdehyde and p-tolunitrile (scheme 9). It could be shown that the stereoisomeric ketoximes 30 are photochemically interconvertible (scheme 12) and that at least one mechanism of formation of 2-(p-tolyl)-quinoline ( 29 ) is the photo-induced cyclisation of p-tolyl-cis-styryl ketoximes (cis- 30 ) (scheme 13). A tentative mechanism for the formation of p-tolual-dehyde is given in scheme 10; the crucial step is the protonation of p-tolunitrile methylide ( 24 , R = CH₃) by methanol at the nitrile carbon atom, after which hydrolysis yields the aldehyde.     

Regioselective aerobic oxidation of bis-sulfides into monosulfoxides

The cobalt(II) acetylacetonate/aldehyde-promoted aerobic oxidation of three bis-sulfides of general formula R¹-SCH₂CH₂S-R², where R¹ is a heterocycle and R² is p-tolyl, provides a method to functionalise selectively the sulfur atom bonded to the p-tolyl moiety leading to the corresponding monosulfoxides. The same chemoselectivity and little diastereoisomeric excess (10%) was achieved by submitting to oxidative conditions the chiral bis-sulfide (S)-R³-SCH₂CH(CH₃)CH₂-SR⁴ (R³=benzothiazolyl, R⁴=p-tolyl).     

Living Carbocationic Polymerization. LVII. Kinetic Treatment of Living Carbocationic Polymerization Mediated by the Common Ion Effect

Abstract

The effect of anion concentration on the apparent rate constant of polymerization k^A _p of isobutylene (IB) induced by the 2-chloro-2,4,4-trimethylpentane (TMPCl)/TiCl₄ initiating system using the CH₂Cl₂/nC₆H₁₄ (60/40 v/v) solvent system at ?40 and ?80°C was studied by the use of nBu₄NCl. Computer simulation has shown that k^A _p decreases several orders of magnitude upon the addition of even a very small amount of common anion TiCl^?- ₅ to the charge. The rate of change is reduced in the concentration range of experimental interest. It was concluded that the decrease of k^A _p with increasing TiCl ^?- ₅ concentration is mainly due to the decreasing contribution of propagation by free ions. The contribution (%) of propagation by free ions to the apparent rate of propagation was calculated.     

Thallium(III) coordination compounds: chemical information from 205Tl NMR longitudinal relaxation times

²⁰⁵Tl longitudinal relaxation rate measurements were performed on several thallium(III) complexes with the composition Tl(OH)_n(H₂O)_6?n^(3?n)+ (n = 1,2), Tl(Cl)_n(H₂O)_m?n^(3?n)+, Tl(Br)_n(H₂O)_m?n^(3?n)+ (m = 6 for n = 1–2, m = 5 for n = 3, m = 4 for n = 4), Tl(CN)_n(H₂O)_m?n^(3?n)+ (m = 6 for n = 1–2, m = 4 for n = 3–4) in aqueous solution, at different magnetic fields and temperatures. ¹³C and ²D isotopic labelling and ¹H decoupling experiments showed that the contribution of the dipolar relaxation path is negligible. The less symmetric lower complexes (n < 4) had faster relaxation rate dominantly via chemical shift anisotropy contribution which depended on the applied magnetic field: T₁ values are between 20 and 100 ms at 9.4 T and the shift anisotropy is Δσ = 1000–2000 ppm. The tetrahedral complexes, n = 4, relax slower; their T₁ is longer than 1 s and the spin–rotation mechanism is probably the dominant relaxation path as showed by a temperature dependence study. In the case of the TlCl₄^? complex, presumably a trace amount of TlCl₅^2? causes a large CSA contribution, 300 ppm. Since the geometry and the bond length for the complexes in solution are known from EXAFS data, it was possible to establish a correlation between the CSA parameter and the symmetry of the complexes. The relaxation behaviour of the Tl–bromo complexes is not in accordance with any known relaxation mechanism. Copyright © 2002 John Wiley & Sons, Ltd.     

Reactions of trichloro(cyclopentadienyl)titanium(IV) with 1,5-diarylthiocarbazones

Summary The synthesis and characterization of the complexes from the reactions of trichloro(cyclopentadienyl)titanium(IV) with 1,5-diarylthiocarbazones (aryl=phenyl,o-tolyl,o-chlorophenyl,p-tolyl,p-chlorophenyl, or 3,5-dimethylphenyl) are reported. They are of the types CpTi(HDz)Cl₂ and CpTi(HDz)₂Cl (Cp=cyclopentadienyl, HDz^–=the mono-anion of a 1,5-diarylthiocarbazone, H₂Dz). The compounds are nonelectrolytes in dimethylformamide (DMF). In solid state, the far i.r. spectra of CpTi(HDz)Cl₂ indicate the complexes to be dimeric, involving Cl-bridges.     

Star-shaped polymers by living cationic polymerization. VII. Amphiphilic graft polymers of vinyl ethers with hydroxyl groups: Synthesis and host–guest interaction

Amphiphilic graft polymers of vinyl ethers (VEs) ( 6 ) where each branch consists of a hydrophilic polyalcohol and a hydrophobic poly(alkyl vinyl ether) segment were prepared on the basis of living cationic polymerization, and their properties and functions were compared with the corresponding amphiphilic star-shaped polymers. In toluene at ?15°C, the HI/ZnI₂-initiated living block polymer 2 of an ester-containing VE (CH₂? CHOCH₂CH₂OCOCH₃) and isobutyl VE (IBVE) was terminated with the diethyl 2-(vinyloxy)ethylmalonate anion [ 3 ; ^ΦC(COOEt)₂CH₂CH₂OCH ? CH₂] ( 2/3 = 1/2 mole ratio) to give a macromonomer ( 4 ), H[CH₂CH(OCH₂CH₂OCOCH₃)] _m-[CH₂CH(OiBu)]_n? C(COOEt)₂CH₂CH₂OCH ? CH₂ (m = 5, n = 15; M?_n = 2600, M?_w/M?_n = 1.13, 1.10 vinyl groups/chain). Subsequently, 4 was homopolymerized with HI/ZnI₂ in toluene at ?15°C. In 3 h, 85% of 4 was consumed and a graft polymer ( 5 ) was obtained [M?_w = 15000, DP_n (for 4 ) = 6]. The apparent M?_w (10,900) of 5 by size-exclusion chromatography (SEC) is smaller than that by light scattering as well as that (18,300) by SEC of the corresponding linear polymer with the almost same molecular weight, indicating the formation of a multi-branched structure. Hydrolysis of the pendant esters in 5 gave the amphiphilic graft polymer 6 where each branch consists of a hydrophilic polyalcohol and a hydrophobic poly(IBVE) segment. The graft polymer 6 was found to interact specifically with small organic molecules (guests) with polar functional groups, and 6 differed in solubility and host-guest interaction from the corresponding star-shaped polymer. © 1993 John Wiley & Sons, Inc.     

Studies in organic mass spectrometry. XXII–Evidence for the existence of cyclic oxonium ions in the gas phase

The electron impact induced loss of a phenoxy radical from the molecular ions of α,ω-bis-aryloxy alkanes ΦO(CH₂)_nOΦ ( 1 _n; n = 2–7) and F-p-C₆H₄(CH₂)_nOΦ(2_n; n = 2?5) is the result of functional group interaction. Labelling data provide conclusive evidence for the O-aryl tetra-hydrofuranium and O-aryl tetrahydropyranium structures of the resulting decomposing species (lifetimes between 10^?6 and 10^?5 s) in the case of n = 4 and 5, respectively. Evidence is presented for the occurrence of phenyl participation in the loss of ΦOH from the molecular ions of the lower homologues of 1 _n and 2_n (n = 2, 3).     

Mass spectrometric monitoring of oxidation of aliphatic C6–C8 hydrocarbons and ethanol in low pressure oxygen and air plasmas

Experimental and theoretical studies on the oxidation of saturated hydrocarbons (n‐hexane, cyclohexane, n‐heptane, n‐octane and isooctane) and ethanol in 28 Torr O₂ or air plasma generated by a hollow cathode discharge ion source were made. Ions corresponding to [M + 15]⁺ and [M + 13]⁺ in addition to [M ? H]⁺ and [M ? 3H]⁺ were detected as major ions where M is the sample molecule. The ions [M + 15]⁺ and [M + 13]⁺ were assigned as oxidation products, [M ? H + O]⁺ and [M ? 3H + O]⁺, respectively. By the tandem mass spectrometry analysis of [M ? H + O]⁺ and [M ? 3H + O]⁺, H₂O, olefins (and/or cycloalkanes) and oxygen‐containing compounds were eliminated from these ions. Ozone as one of the terminal products in the O₂ plasma was postulated as the oxidizing reagent. As an example, the reactions of C₆H₁₄^+? with O₂ and of C₆H₁₃⁺ (CH₃CH₂CH⁺CH₂CH₂CH₃) with ozone were examined by density functional theory calculations. Nucleophilic interaction of ozone with C₆H₁₃⁺ leads to the formation of protonated ketone, CH₃CH₂C(=OH⁺)CH₂CH₂CH₃. In air plasma, [M ? H + O]⁺ became predominant over carbocations, [M ? H]⁺ and [M ? 3H]⁺. For ethanol, the protonated acetic acid CH₃C(OH)₂⁺ (m/z 61.03) was formed as the oxidation product. The peaks at m/z 75.04 and 75.08 are assigned as protonated ethyl formate and protonated diethyl ether, respectively, and that at m/z 89.06 as protonated ethyl acetate. Copyright © 2016 John Wiley & Sons, Ltd.     

Intramolecular easily polarizable hydrogen bonds with anilides of 1-piperidine carboxylic acids

IR spectra are plotted from anilides of 1-piperidine carboxylic acids C₅H₁₀N(CH₂)_n CONHC₆H₄R in CHCl₃ and CDCl₃ solutions. In the cases of n = 1 and n = 4, weak intramolecular (NH?N) hydrogen bonds are formed. An asymmetrical energy surface occurs and the proton is present at the N of the anilide group. In the cases of n = 2 and n = 3, intramolecular proton transfer hydrogen bonds of the types N_BH?N_P ? ^?N_B?H⁺N_p are formed. In contrast to the intramolecular OH? N ? O^?1 ? H⁺N bonds with 1-piperidine carboxylic acids, these bonds to not cause IR continua but two bands: one in the region 3250–3190 and one in the region 2500–2450 cm^?1. The fact that, instead of IR continua, bands are observed is explained by the following: (1) these hydrogen bonds are relatively long; (2) they show only a narrow distribution of bond length; (3) the electrical fields at these bonds are small, since they are strongly screened.     

Gyroscope‐Like Molecules Consisting of PdX2/PtX2 Rotators within Three‐Spoke Dibridgehead Diphosphine Stators: Syntheses,Substitution Reactions,Structures, and Dynamic Properties

Threefold intramolecular ring‐closing metatheses of trans‐[MCl₂(P{(CH₂)_mCH?CH₂}₃)₂] are effected with Grubbs’ catalyst. Following hydrogenation catalyzed by [RhCl(PPh₃)₃], the title complexes trans‐[MCl₂(P((CH₂)_n)₃P )] (n=2m+2; M/n=Pt/14, 4 c ; Pt/16, 4 d ; Pt/18, 4 e ; Pd/14, 5 c ; Pd/18, 5 e ) and sometimes isomers partly derived from intraligand metathesis, trans‐[MCl₂{P(CH₂)_n(CH₂)_n}P (CH₂)_n)] ( 4′c–e , 5′e ), are isolated. These react with LiBr, NaI, and KCN to give the corresponding MBr₂, MI₂, and M(CN)₂ species (58–99 %). ¹³C NMR data show that the MX₂ moieties rapidly rotate within the diphosphine cage on the NMR timescale, even at ?120 °C. The reaction of 4 c and KSCN gives separable Pt(NCS)₂ and Pt(NCS)(SCN) adducts ( 13 c , 28 %; 14 c , 20 %), and those of 4 c , e and Ph₂Zn give PtPh₂ species ( 15 c , 61 %; 15 e , 90 %). ¹³C NMR spectra of 13 c – 15 c show two sets of CH₂ signals (ca. 2:1 intensity ratios), indicating that MX₂ rotation is no longer rapid. Reactions of 4 c or 4′c and excess NaC?CH afford the free diphosphines P{(CH₂)₁₄}₃P (91 %) and (CH₂)₁₄P (CH₂)₁₄P(C H₂)₁₄ (90 %). The latter has been crystallographically characterized as a bis(BH₃) adduct. The crystal structures of eight complexes with P(CH₂)₁₄P linkages (PtCl₂, PtBr₂, PtI₂, Pt(NCS)₂, PtPh₂, PdCl₂, PdBr₂, PdI₂) and 15 e have been determined, and intramolecular distances analyzed with respect to MX₂ rotation. The conformations of the (CH₂)₁₄ moieties and features of the crystal lattices are also discussed.     

由3-二茂铁-2-丁烯酸根和1,10-邻菲啰啉构筑的一维链状铅(II)配位聚合物的合成、晶体结构及电化学性质

Pb(OAc)₂•3H₂O, 3-二茂铁-2-丁烯酸钠以及1,10-邻菲啰啉在甲醇中反应得到了铅的配位聚合物: [Pb(m-OOCCH＝C(CH₃)Fc)(m₂-OOCCH＝C(CH₃)Fc)(phen)]_n (Fc＝(h⁵-C₅H₅)Fe(h⁵-C₅H₄); phen＝1,10-邻菲啰啉). 单晶测试表明: 每个铅离子为六配位, 其中4个氧原子来自4个3-二茂铁-2-丁烯酸根, 另2个氮原子来自邻菲啰啉; 相邻的铅离子通过3-二茂铁-2-丁烯酸根的单齿和双齿氧原子桥连形成了一个无限的一维长链. 研究了标题化合物在DMF溶液中的电化学性能.