Copolymerization in solid solutions

The Kinetics of Growth of Metallo‐supramolecular Polyelectrolytes in Solution

“…In agreement with previously published data, [23,33,34] the conductivity decreases with the addition of the metal acetate solution to the ligand solution. The conductivity of acetic acid solution (75 vol %) is with 200(AE 15) mScm À1 considerably lower than that of the acetic acid solutionc ontaining the ligand with 580(AE 15) mScm À1 .T he conductivity minimum occurs at av olumeo fV Fe 2þ = 30.6, V Co 2þ = 27.7, and V Ni 2þ = 29.4 mL, which corresponds to av olume ratio of V Fe 2þ =V L = 1.020, V Co 2þ =V L = 0.923, and V Ni 2þ =V L = 0.980.…”

“…However, if Zn 2 + is used as am etal ion in acetic acid solution (75 vol %) with pH 1.8, [ZnL] 2 + complexes predominate, that means, no long chains form. These resultsa re in agreement with Monte Carlo simulations presented by Dormidontova et al [33] They showed that the maximum degree of polymerization in metallo-supramolecular polymers occurs at the metal ion-to-ligandr atio of y = 1.00. The chain length reaches its maximum at y = 1.00.…”

“…Figure 3s hows the calculated average number of MEPE repeatu nits per chain, hni,a sf unction of the pH as well as of the metal ion-to-ligand ratio, y. [33] In case of the nonlinearc hain-lengthd ependence in the proximity of y = 1.00, small changes in y cause large variations in chain length, for example, by experimental errors and impurities ( Figure 3). In case of Fe 2 + , lg[K 2 ]i sa round twice as high as lg[K 1 ]( Ta ble 1) and the maximum of lghni is 5.…”

“…The chain length reaches its maximum at y = 1.00. [23,33,34] The impact of an error in y can be illustrated by calculating the number averaged egree of polymerization, " X n ,i ft he metal ion to ligand ratio, y < 1[ Eqs. The chain length is asymmetricw ith respect to y as shown in Figure 3a.I nc ase of Co 2 + and Ni 2 + where the [29]a re measuredi nw ater with 2,2':6',2''terpyridinea nd bromide as counteri on, while the values from reference [32] are measured in acetonitrile with 4,4-difluoro-8-(6''-methyl-2',2'':6'',2'''-terpyridin-6'-yl)-1,3,5,7-tetramethyl-2,4-diethyl-4-bora-3a,4adiaza-s-indacene as ligand and perchlorate as counter ion.…”

“…[33] Adjusting the metali on to ligandr atio In order to achievethe most accurate metal ion-to-ligand ratio, y = 1.00, ap rotocolw as developed based on conductometry. Thus, it is of paramount importance to adjust the metal ion to ligand ratio, y,a sa ccurately as possible to obtain consistent and reproducible results, in order to arrive at meaningful structure-property relationships.…”