Ecz 600 instrument

All the experiments were performed in an inert atmosphere using a standard glove box and Schlenk techniques. Toluene, hexane, and THF were distilled from benzophenone ketyl. Methylcyclohexane (anhydrous grade) used for the polymerization reactions was purchased from Tokyo Chemical Industry (TCI, Tokyo, Japan) and purified over a Na/K alloy. Sublimed-grade HfCl₄ was purchased from Strem Chemicals (Newburyport, MA, USA) and used as received. The ethylene/propylene mixed gas was purified over trioctylaluminum (0.6 M in methylcyclohexane), in a bomb reactor (2.0 L). The ¹H NMR (600 MHz) and ¹³C NMR (150 MHz) analyses were performed on a JEOL ECZ 600 instrument (Tokyo, Japan). Elemental analyses were performed at the Analytical Center of Ajou University (Suwon, South Korea). The GPC data were obtained in 1,2,4-trichlorobenzene, at 160 °C, using a PL-GPC 220 system equipped with a RI detector and two columns (PLgel mixed-B 7.5 × 300 mm from Varian (Polymer Lab, Palo Alto, CA, USA)). The ligand precursors for 1–6 [33 (link),34 (link)] and compounds 7–8 [35 (link)] were prepared according to the reported method.

Phosphoric acid (85.0%), SA (≥99.0%), (nBuO)₄Ti (97%), and Mg(OH)₂ were purchased from Sigma-Aldrich (St. Louis, MO, USA). BD (99.5%, 18 L scale) was purchased from Duksan (Reagents Duksan, Ansan, Korea). 2-Ethylhexanoic acid was purchased from TCI (Tokyo, Japan). Zn(2-ethylhexanoate)₂ (80 wt% in mineral spirits), and Mn(2-ethylhexanoate)₂ (40 wt% in mineral spirits) were purchased from Alfa Aesar (Ward Hill, MA, USA). ¹H NMR (600 MHz), ¹³C NMR (150 MHz), and ³¹P NMR (243 MHz) analyses were performed by using a JEOL ECZ 600 instrument (JEOL, Tokyo, Japan). The GPC data were obtained in CHCl₃ at 40 °C using a Waters Millennium apparatus with polystyrene standards. The T_m, T_g, T_c, T_cc and their enthalpy (ΔH) data were determined with DSC 200 F3 Maia (NETZSCH, Bavaria, Germany) at a heating rate of 10 °C/min. For tensile studies, the polymer samples were compressed between hot plates at 130 °C. The pressure was applied incrementally, starting from 1 MPa to 5 MPa, with each 1 MPa increment lasting 5 min, totaling 20 min. Subsequently, the pressure was increased from 5 MPa to 10 MPa, with each 1 MPa increment lasting 10 min, accumulating to a total duration of 60 min. Tensile tests were performed according to ASTM D882 [65 ] using a Instron 3367 UTM (Instron, MA, USA) at a drawing rate of 50 mm/min with a gauge length of 50 mm.

NMR spectra were recorded at 500 MHz (¹H) and 125 MHz (¹³C) using an ECA 500 instrument (JEOL Ltd., Tokyo, Japan) or at 600 MHz (¹H) and 150 MHz (¹³C) with an ECZ 600 instrument (JEOL Ltd.). Chemical shifts were administered in parts per million (ppm), with acetone (δ ¹H 2.23 ppm, δ ¹³C 31.1 ppm) used as an internal reference for samples measured in D₂O solutions. Signals were assigned based on the results of the heteronuclear single-quantum coherence (HMQC) and heteronuclear multiple-bond coherence (HMBC) experiments. ¹H NMR chemical shifts of the overlapping signals were obtained from the center of the cross peaks in the 2D spectra.