The kinetic behavior of the halato telechelic polymer (N,lV-dimethyl-.ÍV-[3-( l-pyrenyl)propyl]ammonio)trifluoromethanesnlfonate-end-capped poly(tetrahydrofuran) (POLYPROBE) in tetrahydrofuran is investigated by global compartmental analysis of the fluorescence decay surface. At low POLYPROBE concentrations the emission decays monoexponentially. When an analogous end-capped halato telechelic polymer without the pyrene chromophore ((Ñ,A,A-triethylammonio)trifluoromethanesulfonate-end-capped poly(tetrahydrofuran), POLYSALT) is added to solutions containing a low POLYPROBE concentration, the emission can be fitted by a biexponential decay function. From these observations it is concluded that the second excited-state species in the POLYPROBE-POLYSALT system is POLYPROBE involved in ion aggregation due to dipole-dipole or ion-dipole interaction. At higher POLYPROBE concentrations, without added POLYSALT, a triexponential decay function is needed to describe the emission. The third excited-state species is a POLYPROBE excimer, which can be formed via two pathways: either intermolecularly when a locally excited POLYPROBE encounters a ground-state POLYPROBE or intramolecularly when an aggregate of two POLYPROBE molecules rearranges. From the global compartmental analysis in which the value of one of the rate constants is scanned, it is found that the bimolecular processes are slowed down by the presence of the polymer chain, while intramolecular rearrangements are not affected.

The kinetics of the excited-state processes of the charged fluorescent probe N,N,N-trimethyl-3-( l-pyreny1)-1 -propanaminium perchlorate (PROBE) in tetrahydrofuran are reported. At very low concentrations PROBE decays monoexponentially with a lifetime z of 236 f 1 ns, from which b 1 = l/z = 4.2 x lo6 s-l is obtained. Upon addition of the quaternary ammonium salt N,N,N-trimethyl-l -dodecanaminium perchlorate a biexponential decay function is needed to describe the decay traces. The second excited state is the aggregated PROBE. This aggregation is due to dipole-dipole or ion-dipole interactions. The rate constant values of the kinetic Scheme (Scheme 4) are obtained by global bicompartmental analysis: bl = b 2 , kzl = (42 f 7) x lo9 M-' s-l; k12 = (5.7 f 0.1) x lo7 s-l. When the concentration of PROBE itself is varied, a triple-exponential decay function adequately describes the decay surface. The third excited-state species is a PROBE excimer, which can be formed through two different pathways: either intermolecularly when a locally excited PROBE molecule encounters a ground-state PROBE molecule or intramolecularly when an aggregate of two PROBE molecules rearranges. To resolve the kinetics of this system, global tricompartmental analysis is developed.Even after including the information available from experiments where NJV,N-trimethyl-1 -dodecanaminium perchlorate is added (bl = b2), and the information available from the global triple-exponential analysis (k13 = 0 and k23 = 0) (Scheme 5), the experimental time-resolved data do not allow one to obtain a unique solution for the rate constant values. By scanning the rate constant k31, bounds can be specified for the rate constants: 53 x lo9 < k21 < 60 x lo9 M-' s-l, k31 < 7 x lo9 M-' s-l, 1.5 x lo8 < k12 < 1.7 x lo8 s-l, and k32 < 2 x lo7 s-'. Unique values are obtained for b l , b2, and b 3 : bl = b 2 = (4.25 f 0.01) x lo7 s-l; b3 = (1.92 f 0.03) x lo7 s-l.

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A copolymer of styrene–maleimide has been obtained by reaction of a styrene–maleic anhydride copolymer with ammonia under pressure in acetone solution at 70–90°C. The co(styrene–maleimide) polymer was submitted to Hofmann degradation reaction in aqueous medium and in water–tert‐butyl alcohol solution. In aqueous solution the amine formation is accompanied by partial lactam formation resulting from interaction between acid and amine groups. In water–tert‐butanol this cyclization reaction did not take place, since there was formation of tert‐butyl carbamates. These carbamate groups may be hydrolyzed in acetic acid solution in the presence of hydrochloric acid, and afford free amino groups. In both media, appreciable hydrolysis proceeds simultaneously with the Hofmann reaction, so that the number of carboxyl groups exceeds by far the number of amino groups (75 vs. 20–25%).

The excited-state processes of the halato-telechelic polymer bis [(N,N-dimethyl-N-[3-(1-pyrenyl)propyl]ammonio)trifluoromethanesulfonate]-end-capped poly(tetrahydrofuran) at low concentrations are investigated by time-resolved fluorescence. The photophysical processes can be described by an intramolecular three-state excited-state model. Such a system is not identifiable in the absence of a priori information. It is possible to perform a global compartmental analysis of the fluorescence decay surface using the scanning technique, based on model compound data previously obtained [Hermans et al., J. Phys. Chem. 1994, 98, 13583 and Hermans et al. Macromolecules 1995, 28, 3380]. The value boundaries on the rate constant for ring closure of the chain ends show that this process is close to diffusion-controlled.