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Aniline (N-R-C 6 H 5 NH) and 1,2,3,4-tetrahydroquinoline (2-R-C 9 H 9 NH) derivatives were ortho-lithiated via conversion of the respective −NH groups to −N(COOLi), followed by treatment with tBuLi. The resulting ortho-lithiated compounds were transformed to ortho-Ph 2 P-substituted derivatives on treatment with Ph 2 P(OPh). Further reaction of the resulting compounds with M(CH 2 Ph) 4 (M = Zr, Hf) afforded a series of Hf and Zr complexes: (2-R-8-Ph 2 PC 9 H 9 N)Hf(CH 2 Ph) 3

Two new bis(amidine) cobalt(II) complexes were rationally designed and efficiently synthesized. The first synthesized cobalt complex was based on a cyclic bis(amidine) ligand with chiral vicinal diphenyl groups. The structure was verified by single-crystal X-ray crystallography. As expected from the ligand structure, the Co−N bonds in this complex were significantly shorter than those found in the corresponding 1,2-diimine cobalt complex. This indicates that the bis(amidine) ligand has better electron-donating capability than the 1,2-diimine ligand. Upon test polymerization of styrene, the complex exhibited a moderate activity of 5.88 × 10 5 g PS/(mol Co h). On the basis of this encouraging result, a new 1,2-diaminobenzene-derived bis(amidine) ligand was efficiently synthesized and used to make the corresponding cobalt(II) complex. When subjected to styrene polymerization, the resulting complex showed unusually high polymerization activity [164 × 10 5 g PS/(mol Co h)] and high conversion (>99%). The resulting polymer was identified as atactic polystyrene by 13 C NMR spectroscopy analysis. The significantly enhanced styrene polymerization activity of the 1,2-diaminobenzene-originated bis(amidine) cobalt(II) complex is attributed to the improved electron-donating capability of the ligand. Article pubs.acs.org/Organometallics

Post-metallocenes were constructed for olefin polymerization using 1,2,3,4,7,8,9,10-octahydro[1,10]phenanthroline and 1,2,3,4-tetrahydro[1,10]phenanthroline derivatives. A series of zirconium complexes - LZrCl2(NHMe2)2 [L = 2,9-H2-C12H12N2 (4), 2,9-Me2-C12H12N2 (5), 2,9-nBu2-C12H12N2 (6), and 2,9-iPr2-C12H12N2 (7)] - and hafnium complexes - LHfCl2(NHMe2)2 [L = 2,9-H2-C12H12N2 (8), 2,9-Me2-C12H12N2 (9), 2,9-nBu2-C12H12N2 (10), and 2,9-iPr2-C12H12N2 (11)] - were synthesized via the reaction of octahydro[1,10]phenanthrolines (2,9-R2-C12H12(NH)2) with (Me2N)2MCl2 (DME). The reaction of 2,9-R2-C12H12(NH)2 with (PhCH2)2ZrCl2 in the presence of a small amount of THF afforded a series of THF adduct analogs, i.e., LZrCl2(THF)2 [L = 2,9-H2-C12H12N2 (12), 2,9-Me2-C12H12N2 (13), 2,9-nBu2-C12H12N2 (14), and 2,9-iPr2-C12H12N2 (15)]. The treatment of 12 and 13 with excess Me3Al resulted in the formation of unexpected complexes, i.e., (η(4)-LAlMe2)ZrCl2(Me) [L = 2,9-H2-C12H12N2 (16) and 2,9-Me2-C12H12N2 (17)], in which the Me2Al unit forms a five-membered ring through binding with the two nitrogen donors and the MeCl2Zr unit slips to an η(4)-binding mode containing the N-C-C-N fragment. The treatment of tetrahydro[1,10]phenanthrolines [2,9-R2-C12NH9(NH)] with M(CH2Ph)4 afforded tribenzyl zirconium complexes LZr(CH2Ph)3 - [L = 2,9-Me2-C12NH9N (18) and 2,9-nBu2-C12NH9N (19)] - and hafnium complexes - LHf(CH2Ph)3 [L = 2,9-Me2-C12NH9N (20), 2,9-nBu2-C12NH9N (21), and 2,9-iPr2-C12NH9N (22)]. The structures of 4, 5, 12, 17, and 22 were elucidated by X-ray crystallography. The newly prepared complexes were screened for ethylene/1-octene copolymerization activity: 12 and 16 were potent catalysts (activities of 74 × 10(6) g mol-Zr h(-1) at ∼120 °C under 30 bar ethylene) for the production of wax-like low-molecular weight polyethylene (Mn: ∼5000), which is widely used in industry.

In-situ U-Pb geochronology and Hf isotopic studies of zircons from the Pre-Tertiary basement complex and Eocene rocks of the Central Range of Taiwan were carried out to elucidate the history of detrital zircons older than 2.3 Ga. Zircons from the eastern Backbone Range and Eastern Central Range show Paleoproterozoic to late Neoarchean ages (2.3-≥2.5 Ga), whereas those from the Hsuehshan Range yield Neoarchean to Mesoarchean ages (2.6-3.2 Ga). The ε Hf (T) for the Paleoproterozoic to late Neoarchean zircons varies from -7.4 to +5.1, implying both juvenile crustal growth and reworking of old crusts. This dual origin could extend back to Mesoarchean-Paleoarchean (3.0-3.4 Ga) based on Hf isotopic model ages. Consistent but narrower ε Hf (T) values and Hf crustal model ages for zircons from Taiwan compared to Cathaysia suggest a possible common origin for these zircons, although Taiwan has a generally younger crustal evolution history than SE China.