Initiator system

All polymers were synthesised on a Biotage Initiator System (Biotage, Sweden) equipped with Robot Eight. The temperature was monitored with an infrared sensor. The polymerisations were performed at a low absorption level after prestirring for 10 seconds at room temperature.

Solvents were purchased
from commercial suppliers and dried before use if needed. Microwave
reactions were performed with a Biotage Initiator+ system. Purification
via flash column chromatography was conducted with a Biotage Isolera
system and silica gel (VWR, mesh 40–63 μm). The dimeric
metal precursor [Ru(p-cymene)Cl₂]₂ was synthesized according to the literature.^{36 (link)} The general numbering of carbons and hydrogens and the
corresponding NMR spectra of ligands 2–9 and complexes 1a–9a were described
in the Supporting Information (pp 3–16). ¹H, ¹³C, and 2D NMR spectra were recorded at 298
K on a Bruker AV III 600 or AV NEO 500 spectrometer at 600.25/500.10
MHz (¹H) and 150.95 MHz (¹³C). Elemental analyses
were conducted by the microanalytical laboratory of the faculty of
chemistry of the University of Vienna with a Eurovector EA 3000 (2009)
equipped with a high temperature pyrolysis furnace (HT, Hekatech,
Germany, 2009).

O-salicylaldehyde; 3-amino pyridine; ethanol; nitrate salts of Al(III), Ba(II), Cd(II), Co(II), Cu(II), Fe(III), Mn(II), Ni(II), and Zn(II), and sulfate salt of Fe(II) were all purchased from Sigma-Aldrich (Steinheim, Germany) and dissolved in ultrapure water (Direct-Q 5 UV water purification system, Millipore, Burlington, MA, USA). The microwave reactions were carried out in a Biotage Initiator system (Biotage, Sweden), the temperature and time were preset as required, and the pressure was monitored and indicated. The identity of the products was determined by FTIR and NMR. FTIR analysis was performed on a Spectrum BX FTIR spectrometer (PerkinElmer, Waltham, MA, USA). The ¹H- and ¹³C-NMR spectra were recorded on a JNM-ECZR series 600 MHz spectrometer (JEOL, Tokyo, Japan) operating at 600 and 100 MHz, respectively, using DMSO-d6 as a solvent. The NMR is equipped with a Delta™ NMR data processing software. UV–VIS spectra were carried out using an Agilent 8453 spectrophotometer (Agilent, Santa Clara, CA, USA) in a 1.0 cm quartz cuvette. Fluorescence studies were performed on a PerkinElmer LS 45 Fluorescence spectrometer (PerkinElmer, Waltham, MA, USA) using a 1.0 cm quartz cuvette with a scan speed of 700 nm min⁻¹, and an excitation and emission slit of 10 nm each.