New metallomesogenic polymers built by self-assembly of non-mesomorphic stilbazole dimers and CF3SO3Ag through coordination bonds

Supramolecular liquid-crystalline main-chain polymers have been obtained by self-assembly of non-mesomorphic bifunctional ligands and a transition metal ion. Stibazole dimers, bis[2-(2-{4-[2-(4-pyridyl)vinyl]phenoxy}ethoxy)ethyl] ether (1) and 1,2-bis[2-(2-{4-[2-(4-pyridyl)vinyl]phenoxy}ethoxy)ethoxy]benzene (2) have been synthesized and complexed with silver trifluoromethanesulfonate (CF₃SO₃Ag). The metallomesogenic polymeric complexes formed by coordination bonds between the pyridyl groups of the stilbazole dimers and the silver ion exhibit smectic phases.     

Chemistry of 6 -pyrido[4,3- ]carbazoles part II: synthetic approaches to 6 -9-methoxy-5, 11-dimethylpyrido[4,3- ] fluorenes

Synthetic approaches to 6 -9-methoxy-5, 11-dimethylpyrido[4,3- ] fluorene are described, thus 2-[1-(4-pyridyl)ethyl]6-methoxyindanone has been reacted with vinylmagnesium bromide to yield 2-[1-(4-pyridyl)ethyl]-6 methoxy-1-vinyl-1-indanol. However, on dehydration this compound rearranges to 2-[1-(4-pyridyl)ethyl]-3-ethylidene-5-methoxyindene rather than the required isomer 3-ethylidine-2-[1-(4-pyridyl)ethyl]-5-methoxyindane needed fro pericyclic ring-closure to the pyrido[4,3- ]fluorene system. Reaction of -2-[1-methyl-1-(4-pyridyl)methylene]-6-methoxyindanone with ethylene triphenylphosphorane similarly gives 6-methoxy-spiro-2-[1-(2,3-dimethyl-3-(4-pyridyl)-cyclopropyl) indanone rather than the desired indane.     

Development of Carbazole and Bipyridine Copolymers as Novel Photovoltaic Materials

Summary: A novel acrylate polymer with a carbazole pendant group and bipyridine derivatives as side chains was synthesized, in which derivatives of bipyridine as electro-optic chromophores and carbazole as photoconductive moiety were covalently linked to the acrylate backbone. 2–(Carbazol-9-yl)ethyl methacrylate (CEM) and methacrylic 2-[5-(2-{5,5′-dimethyl-6′-[2-(5-pentylthiophen-2-yl)vinyl]-3,3′-bipyridin-6-yl}vinyl)thiophen-2-yl]ethyl methacrylate (BiPy) were synthesized and then copolymerized to give 99:1, 98:2, 92:8 (mol/mol) CEM/BiPy copolymers. Films of the copolymers blended with poly(3-octylthiophene) (P3OT) or poly(3-decylthiophene) (PDT) and sandwiched between the transparent ITO and Al electrode were examined for photovoltaic properties.     

Helix-sense-selective copolymerization of phenyl[bis(2-pyridyl)]methyl methacrylate,diphenyl(2-pyridyl)methyl methacrylate and triphenylmethyl methacrylate with chiral anionic initiators

Optically active poly[triphenylmethyl methacrylate-co-phenyl[bis(2-pyridyl)]methyl methacrylate] (poly[TrMA-co-PB2PyMA], poly[diphenyl(2-pyridyl)methyl methacrylate-co-phenyl[bis(2-pyridyl)]methyl methacrylate] (poly[D2PyMA-co-PB2PyMA]), and poly[triphenylmethyl methacrylate-co-diphenyl(2-pyridyl)-methyl methacrylate] (poly[TrMA-co-D2PyMA]) were prepared by helix-sense-selective copolymerization with complexes of organolithium with (−)-sparteine [(−)Sp],(S, S)-(+)- and (R, R)-(−)-2,3-dimethoxy-1,4-bis(dimethylamino)butane [(+)- and (−)DDB], and (S)-(+)-2-(1-pyrrolidinylmethyl)pyridine [(+)PMP] as anionic initiators in toluene at low temperature. The copolymers obtained with (−)Sp and (+)DDB or (−)DDB complexes of organolithium showed low optical activity, but to [(+)PMP] complex with N,N′-diphenyleneamine monolithium amide [(+)PMP–DPEDA–Li)] was effective in synthesizing copolymers of high optical rotation ([α] about +320 to + 370°) which were comparable to those of corresponding homopolymers with one-handed helical structure. The optical rotations of poly[TrMA-co-PB2PyMA] and poly[TrMA-co-D2PyMA] were much more stable than that of poly(D2PyMA) or poly(PB2PyMA) in a solution of CHCl₃–2,2,2-trifluoroethanol (10 : 1, v/v) at 25°C, but optical rotation of poly[D2PyMA-co-PB2PyMA] slowly decreased with time in the same conditions. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2127–2133, 1998     

The reaction of 1-azirines with 2-pyridyl isothiocyanate: Possible approaches to benzodiazepine and benzodiazepine derivatives

The structure of the dimer ( 5 ) from 2-pyridyl isothiocyanate ( 1 ) has been confirmed by ¹³C nmr spectral studies. The cycloaddition of 2-pyridyl isothiocyanate with 1-azirines results in the formation of thiazoles ( 10 ). Thermal decomposition of the vinyl azide ( 14 ) gives the pyrrole ( 15 ) and the pyridazine ( 16 ) instead of 2-(2-pyridyl)-1-azirine ( 12 ).     

Polymers of the vinyl esters of perchlorocyclopentadiene adducts of petroselinic and oleic acids

Homopolymers of vinyl 5-(1,4,5,6,7,7-hexachloro-3-undecylbicyclo [2.2.1]5-hepten-2-yl)-pentanoate and vinyl 8-(1,4,5,6,7,7-hexachloro-3-octylbicyclo [2.2.1]5-hepten-2-yl)-octanoate were prepared, as well as their copolymers with a vinyl tetrahydroabietate—tetrahydropimarate mixture, vinyl 12-hydroxystearate, and vinyl chloride. The vinyl octanoate—12-hydroxystearate copolymer gave light-weight urethane foams with practically no volume change upon humid aging. The vinyl pentanoate and vinyl octanoate monomers lose hydrogen chloride during polymerization. The vinyl pentanoate homopolymer was hydrolyzed in an attempt to establish the position of the loss of hydrogen chloride. Fractionation of vinyl chloride copolymers of the vinyl petanoate and the vinyl octanoate derivatives showed that they possessed a rather homogeneous composition. Incorporation of the vinyl pentanoate monomer in a poly(vinyl chloride) copolymer imparted some internal plasticization with serious loss of tensile strength.     

Base- and acid-catalyzed condensation reactions of reissert compounds with vinylpyridines

The hydrochloric acid-catalyzed condensation of 2-p-anisoyl-1,2-dihydroisoquinaldonitrile ( 3 ) with 2-vinylpyridine gave 2-(1-isoquinolyl)-3-(2-pyridyl)-5-p-anisylpyrrole ( 4 ), and the corresponding reaction of 3 with 4-vinylpyridine afforded 2-(1-isoquinolyl)-3-(4-pyridyl)-5-p-anisylpyrrole (5). The condensation of the lithium salt of 3 with 4-vinylpyridine gave α-(4-pyridyl)-β-(1-iso-quinolyl)-p-methoxypropiophenone ( 10 ), which was cyclized to 2-(4-pyridyl)-3-p-anisylpyrrolo-[2,1-a]isoquinoline (7) by the action of concentrated hydrochloric acid. 2-(4-Pyridyl)-3-phenyl-pyrrolo[2,1-a]isoquinoline ( 6 ) and 2-(2-pyridyl)-3-p-anisylpyrrolo[2,1-a]isoquinoline ( 8 ) were prepared by analogous sequences of reactions.     

Syntheses of Conjugated Polymers for Photonics

Summary: By the Suzuki coupling reaction of 9,9-dioctyl-2,7-bis(1,3,2-dioxaborinan-2-yl)fluorene ( I ) and 3,5-di-tert-butylphenyl 2,5-dibromobenzenesulfonate ( II ) the alternating poly{[9,9-dioctylfluoren-2,7-diyl]-alt-[2-(3,5-di-tert-butyl-phenoxysulfonyl)-1,4-phenylene]} ( III ) was synthesized. Alkaline hydrolysis of III gave a conjugated polyelectrolyte carrying sulfonic acid groups ( IV ). Monomers 2,5-dibromo-3-[2-(pyren-1-yl)vinyl]thiophene and 2,5-dibromo-3-[2-(quinolin-4-yl)vinyl)thiophene were prepared and copolymerized with I to afford poly{[9,9-dioctylfluoren-2,7-diyl]-alt-[3-(2-(pyren-1-yl)vinyl)thiophen-2,5-diyl]} ( V ) and poly{[9,9-dioctylfluoren-2,7-diyl]-alt-[3-(2-(quinolin-4-yl)-vinyl)thiophen-2,5-diyl] ( VI ), respectively. Conjugated backbone of V contains the conjugated pyrene unit in the side chain. Similarly the side chain of VI contains the conjugated quinoline structure unit which can be for instance protonated. By the Suzuki polycondensation reaction of I and of the prepared methyl 3-(2,7-dibromocarbazole-9-yl)propionate ( VII ) the new poly{[9,9-dioctylfluorene-2,7-diyl]-alt-[9-(2-methoxycarbonylethyl)carbazole-2,7-diyl]} ( VIII ) was synthesized and characterized.     

New bis-, tris- and tetrakis(pyrazolyl)borate ligands with 3-pyridyl and 4-pyridyl substituents: synthesis and coordination chemistry

The new ligands dihydrobis[3-(4-pyridyl)pyrazol-1-yl]borate [Bp(4py)]-, hydrotris[3-(4-pyridyl)pyrazol-1-yl]borate [Tp(4py)]-, tetrakis[3-(4-pyridyl)pyrazol-1-yl]borate [Tkp(4py)]-, dihydrobis[3-(3-pyridyl)pyrazol-1-yl]borate [Bp(3py)]-, hydrotris[3-(3-pyridyl)pyrazol-1-yl]borate [Tp(3py)]- and tetrakis[3-(3-pyridyl)pyrazol-1-yl]borate [Tkp(4py)]- are derivatives of the well known bis-, tris- and tetrakis-(pyrazolyl)borate cores, bearing 4-pyridyl or 3-pyridyl substituents attached to the pyrazolyl C3 positions. These pyridyl groups cannot chelate to the metal ions in the poly(pyrazolyl) cavity but are externally directed. Structural studies on a range of metal complexes show how, in many cases, coordination of these pendant pyridyl groups to the M(pyrazolyl)n core of an adjacent metal complex fragment results in formation of coordination oligomers or polymeric networks. [Tl(Bp(3py))], [Tl(Bp(4py))] and [Tl(Tp(4py))] form one-dimensional polymeric chains via coordination of one of their pendant pyridyl units to the Tl(I) centre of an adjacent complex fragment; in contrast, in [Tl(Tp(3py))] coordination of all three pendant pyridyl units to separate Tl(I) neighbours results in formation of a two-dimensional polymeric sheet. In [Tl(Tkp(3py))] and [Tl(Tkp(4py))] the Tl(I) is coordinated by two or three of the four pyrazolyl arms, respectively; bridging interactions of pendant 4-pyridyl groups with adjacent Tl(I) centres result in a two-dimensional sheet forming in each case. In Ag(Tkp(4py)) each Ag(I) ion is coordinated by two pyrazolyl rings, and two bridging pyridyl ligands from other complex units, resulting in a one-dimensional chain consisting of pairs of cross-linked zigzag chains. In contrast to these polymeric coordination networks, the structures of [Cu(Tp(4py))] and [(Tp(3py))Cd(CH3CO2)] are dimers, with a pendant pyridyl residue from the first metal centre attaching to a vacant coordination site on the second, and vice versa; these dimers are stabilised by pi-stacking interactions between sections of the two ligands. [Ni(Tp(3py))2] is monomeric, with an octahedral coordination geometry arising from two tris(pyrazolyl)borate chelates; the array of pendant 3-pyridyl groups is involved only in intramolecular hydrogen-bonding. [(Tp(4py))Re(CO)3] is also monomeric, with a facial arrangement of three pyrazolyl ligands and three carbonyls, with the pendant 4-pyridyl groups not further coordinated. [(Tp(2py))Re(CO)3], based on the related ligand hydrotris[3-(2-pyridyl)pyrazol-1-yl]borate, has a similar fac-(CO)3(pyrazolyl)3 coordination geometry.     

Reactions of 3-methyl-1-(2-pyridyl)-4-chloro-5-formyl-6,7-dihydroindazole

The reactions of 3-methyl-1-(2-pyridyl)-, 3-methyl-1-phenyl-, and 3-methyl-1,6-diphenyl-4-chloro-5-formyl-6,7-dihydroindazoles with guanidine and benzo- and 3- and 4-pyridinecarbamidines gave the corresponding 8-substituted 1-methyl-3-(2-pyridyl)-and 1-methyl-3-phenyl-4,5-dihydropyrazolo[5,4-h]quinazolines. With acetic anhydride the same indazole derivatives gave the 4-acetoxy-5-formyl derivatives, and with hydroxylamine they gave4-chloro-5-hydroxyiminomethyl-6,7-dihydroindazoles. Thereactionof4-acetoxyl-1-(2-pyridyl)-5-formyl-6,7-dihydroindazole with hydroxylamine gave 8-methyl-6-(2-pyridyl)-4,5-dihydroisoxazolo[5,4-e]indazole, while dehydration of 5-hydroxyiminomethyl-3-methyl-4-chloro-6,7-dihydroindazole gave the 4-chloro-5-cyano derivative. The reaction of the latter with nucleophilic reagents was investigated.Riga Technical University, Riga, Latvia LV-1658. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1209–1213, September, 1998.     

Pyridyl-substituted [1,3]Dithiolo-[4,5-<Emphasis Type="Italic">b</Emphasis>][1,4]dithiine-2-thiones

We have obtained 5-(2-pyridyl)[1,3]dithiolo[4,5-b][1,4]dithiine-2-thione for the first time by cycloaddition of 2-ethynylpyridine to 4,5-dihydro-1,3-dithioltrithione (isotrithionedithiol). We have studied this thione, 5-(2-pyridyl)- and 5-(4-pyridyl)-5,6-dihydro[1,3]dithiolo[4,5-b][1,4]dithiine-2-thiones by mass spectroscopy and also IR, UV, ¹H and ¹³C NMR spectra. We have determined the crystal and molecular structure of 5-(2-pyridyl)-5,6-dihydro[1,3]dithiolo[4,5-b][1,4]dithiine-2-thione.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 429–434, March, 2005.     

Investigation of nitrogen- and sulfur-containing heterocycles

The corresponding N-(3-pyridyl)hydroxamic acid derivatives were obtained by reductive desulfuration of [2-(ethoxycarbonylmethylthio)-6-chloro-3-pyridyl]hydroxamic acid amide, benzylamide, and morpholide. The amides were synthesized by reaction of [2-(ethoxycarbonylmethylthio)-6-chloro-3-pyridyl]hydroxamic acid ester with diethylaminoethylamine and pyrrolidine. Heating of the ester and morpholide of [2-(ethoxycarbonylmethylthio)-6-chloro-3-pyridyl]hydroxamic acid with H₂SO₄ gives 2-chloropyrido[2,3-b] [1,4]thiazin-6-one.See [1] for communication XXVI.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 676–678, May, 1973.     

Synthesis of Poly（p-phenyleneethynylene）s with Crosslinkable End or Side Groups and Its Solid State Structure and Optical Properties Before and after Crosslinking

Two crosslinkable poly(p-phenyleneethynylene)s(PPEs): poly[2,5-di(2'-ethyl-hexyloxy)-1,4-phenylenee-thynylene] with end-capped vinyl(PPE1) and poly[2,5-di(allyloxy)-1,4-phenyleneethynylene-2,5-di(2'-ethyl-hexyloxy)-1,4-phenyleneethynylene](PPE2) were synthesized. Via the thermal addition reactions of vinyl end groups of PPE1 and allyloxy side groups of PPE2, crosslinked polymers C-PPE1 and C-PPE2 were obtained, respectively. The two polymers were characterized by wide-angle X-ray diffraction(WXRD), ultravio...     

Pyrazolo[5,4-h]quinazolines

The reaction of 1-phenyl- and 4-chloro-5-formyl-3-methyl-1-(2-pyridyl)-6,7-dihydroindazoles with carbamidinopyrrolidine, 4-carbamidinomorpholine, creatine, 2-carbamidinopyrazine, and 2-carbamidino-5-trifluoromethylpyridine gives the corresponding 3,8-substituted 1-methyl-4,5-dihydropyrazolo-[5,4-h]quinazolines and with 2-aminobenzimidazole gives 3-phenyl- and 3-(2-pyridyl)-1-methyl-4,5-dihydrobenzo[b]indazolo[4,5-e]imidazolo[1,2-a]pyrimidines.Riga Technical University, Riga LV-1658, Latvia; e-mail; marina@osi.lv . Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 962–965, July, 2000.     

Nitration of 2- and 4-[2-(2-furyl)vinyl]thiazole derivatives

Nitration of 4-methyl-2-[2-(nitro-2-furyl)vinyl]thiazole with a mixture of concentrated nitric and sulfuric acids leads to 4-methyl-5-nitro-2-[2-(3,5-dinitro-2-furyl)vinyl]thiazole. Under the same conditions 2-methyl- and 2-acetamido-4-[1-R-2-(5-nitro-2-furyl)vinyl]thiazoles (R=CH₃, Cl) are nitrated in the 3 position of the furan ring, 2-amino-4-[1-chloro-2-(5-nitro-2-furyl)vinyl]thiazole is nitrated in the 5 position of the thiazole ring and 2-acetamido-5-nitro-4-[2-(2-furyl)vinyl]thiazole undergoes profound changes. Under the influence of a mixture of of nitric acid and acetic anhydride the latter compound is converted quantitatively to the 5-nitro derivative (with respect to the furan ring), whereas 4-[2-(5-nitro-2-furyl)vinyl]thiazole derivatives do not undergo reaction.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 314–317, March, 1977.     

Novel synthesis of 2,4-bis(2-pyridyl)-5-(pyridyl)imidazoles and formation of N-(3-(pyridyl)imidazo[1,5-a]pyridine)picolinamidines: nitrogen-rich ligands

Heating a neat 1:2 mixture of 2-picolylamine and 2-cyanopyridine followed by treatment of the resultant red gummy substance with aqueous KOH resulted in the isolation of 2,4,5-tris(2-pyridyl)imidazole (1a) as the major product and N-(3-(2-pyridyl)imidazo[1,5-a]pyridine)picolinamidine (2a) in small amounts. Similarly, by using 3-picolylamine, 2,4,-bis(2-pyridyl)-5-(3-pyridyl)imidazole (1b) and N-(3-(3-pyridyl)imidazo[1,5-a]pyridine)picolinamidine (2b) were isolated, and by using 4-picolylamine, 2,4,-bis(2-pyridyl)-5-(4-pyridyl)imidazole (1c) and N-(3-(4-pyridyl)imidazo[1,5-a]pyridine)picolinamidine (2c) were isolated. The plausible mechanism of the formation of 1a-c and 2a-c is delineated.     

Cycloaddition reactions of cyclic ketene-N,S-acetals with 1,2,4,5-tetrazines

Reaction of 3,6-diphenyl-, 3,6-bis(2-pyridyl)- and the unsubstituted 1,2,4,5-tetrazine with 4,5-dihydro-1-methyl-2-(methylthio)pyrrole ( 2 ) and 1-raethyl-2-(methylthio)-4.5,6,7-tetrahydroazepine ( 3 ) gives 4,7-di-R-2,3-dihydro-1-methylpyrrolo[2,3-d]pyridazine ( 4 , R = phenyl, 2-pyridyl, hydrogen) and 6,9-di-R-1-methyl-2,3,4,5-tetrahydropyridazino[4,5-6]azepine ( 5 ), R = phenyl, 2-pyridyl, hydrogen), respectively, in reasonable to good yields. The compounds 4 (R = phenyl, hydrogen) are converted into their corresponding 1-methylpyrrolo-[2,3-d]pyridazines 6 by reaction with potassium permanganate in butanone. Reaction of 3-phenyl-1,2,4,5-te-trazine with 2 and 3 leads to the exclusive formation of the 7-phenyl isomer 4d and 9-phenyl isomer 5d , respectively, indicating that the cycloaddition is regiospecific. The mechanism is discussed.     

Theoretical studies on the spectroscopic properties and the substituent effects of pyridyl triazole Os(II) complexes

To explore the spectroscopic properties of pyridyl triazole Os(II) complexes and how the substituent effects affect the spectroscopic properties of [Os(ptz)₂L₂] (L=PH₃; ptzH=(2-pyridyl)-1,2,4-triazole) (1), [Os(bptz)₂L₂] (bptzH=3-tert-butyl-5-(2-pyridyl)-1,2,4-triazole) (2), [Os(fptz)₂L₂] (fptzH=3-(trifluoreomethyl)-5-(2-pyridyl)-1,2,4-triazole) (3), and [Os(fbtz)₂L₂] (fbtzH=3-(trifluoreomethyl)-5-(4-tert-butyl- 2-pyridyl)-1,2, 4-triazole) (4), the density functional theory (DFT) method at the B3LYP level was used to optimize the geometrical structures in the ground and excited state. The absorption and emission properties of the dichloromethane solution were predicted at the time-dependent density functional theory (TD-DFT, B3LYP) level associated with the PCM solvent effect model, the transitions characters of them were assigned. Important correlations between substituent effects and emission spectra and the quantum yield have been obtained by comparing and analyzing the calculated results.     

ELEMENTAL SULFUR REACTIONS WITH 2-PICOLINE

Abstract

A study of the reaction of the elemental sulfur with 2-picoline is reported. The process was carried out at the boiling point of the 2-picoline under argon. After removing unreacted solids, the reaction products were identified by means of LC. GC and GC-MS. The following products have been identified by mass spectrometry: 1,2-di/2-pyridyl/-ethane. 1,2-di/2-pyridyl/-ethene. 2-methyl-x-[/2-pyridyl/methyl]pyridines, 2-mercapto-methyl-[x/2-pyridyl/methyl]-pyridines, l-mercapto-1,2-di/2-pyridyl/-ethane, 5,6-di/2-pyridyl/-5H-cyclopenta-[b]pyridine, 5,6-di/2-pyridyl/-7H-cyclopenta[b]pyridine, 1,2,3-tri/2-pyridyl/-propane. 1,2-di/2-pyridyl/-1-[x-/2-methyl/-pyridyl]-ethane, 5,6-di/2-pyridyl/-7-[/2-pyridyl/methyl]-7H-cyclopenta[b]pyridine, 5,6-di/2-pyridyl/-5-[/2-pyridyl/-methyl]-5H-cyclopenta-[b]pyridine. Di{7-[5,6-di/2-pyridyl/-7H-cyclopenta[b]pyridyl]} sulfide and di(7-[5,6-di/2-pyridyl/-7H-cyclopentalblpyridyl]} disulfide.     

Adsorption of poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) polymers on zinc, zinc oxide, iron, and iron oxide surfaces

The adsorption of poly(vinyl formamide) (PVFA) and the statistic copolymers poly(vinyl formamide-co-vinyl amine) (PVFA-co-PVAm) onto zinc and iron metal particles as well as their oxides was investigated. The adsorbates were characterized by means of XPS, DRIFT spectroscopy, wet chemical analysis, and solvatochromic probes. Dicyano-bis-(1,10-phenanthroline)-iron(II) (1), 3-(4-amino-3-methylphenyl)-7-phenyl-benzo-[1,2-b:4,5-b']difuran-2,6-dione (2), and 4-tert-butyl-2-(dicyano-methylene)-5-[4-(diethylamino)-benzylidene]-Δ(3)-thiazoline (3) as solvatochromic probes were coadsorbed onto zinc oxide to measure various effects of surface polarity. The experimental findings showed that the adsorption mechanism of PVFA and PVFA-co-PVAm strongly depends on the degree of hydrolysis of PVFA and pH values and also on the kind of metal or metal oxide surfaces that were employed as adsorbents. The adsorption mechanism of PVFA/PVFA-co-PVAm onto zinc oxide and iron oxide surfaces is mainly affected by electrostatic interactions. Particularly in the region of pH 5, the adsorption of PVFA/PVFA-co-PVAm onto zinc and iron metal particles is additionally influenced by redox processes, dissolution, and complexation reactions.