Octahedral Group 4 Metal Complexes That Contain Amine, Amido, and Aminopyridinato Ligands:  Synthesis, Structure, and Application in α-Olefin Oligo- and Polymerization

Abstract

The reaction of trimethylsilyl-substituted 2-aminopyridines with mixed chloro(dialkylamido)metal complexes (titanium and zirconium) leads via amine elimination to octahedral group 4 metal complexes that contain amine, amido, and aminopyridinato ligands. The X-ray crystal structure analyses of (4-Me-TMS-APy)(NMe(2))(HNMe(2))TiCl(2) (1) (crystallographic data: P2(1)/c (No. 14), monoclinic, a = 16.754(2) Å, b = 14.395(2) Å, c = 17.890(3) Å, beta = 110.28(1) degrees, Z = 8) and (6-Me-TMS-APy)(NEt(2))(HNEt(2))ZrCl(2) (2) (crystallographic data: P2(1)/n (No. 14) monoclinic, a = 10.125(1) Å, b = 16.331(1) Å, c = 15.276(2) Å, beta = 93.90(1), Z = 4) prove the compounds to be mononuclear with a cisoid arrangement of the two chloro ligands embedded in a reactive pocket determined by the steric demand of the three nitrogen containing ligands. Oligo- and polymerization studies with propene and 1-butene reveal the following results. First, 1 is a remarkably active precatalyst in contrast to the very low activity of 2. Second, MAO, a 1:1 mixture of i-Bu(3)Al/B(C(6)F(5))(3) (homogeneous polymerization) and ethylaluminum sesquichloride (if 1 is incorporated in a MgCl(2)-matrix) have shown to be the most active cocatalysts. Third, the polymers and oligomers are atactic.

Highly active/selective and adjustable zirconium polymerization catalysts stabilized by aminopyridinato ligands

“…Yield: 0.52 g (54%). Elemental analyses for C 50 H 58 Cl 2 N 4 Zr (877.15): C,68.5;H,6.7;N,6.4. Found: C,68.1;H,7.1;N,6.4%.…”

Preparation of Two Maleic Acid Sulfonamide Salts and Their Copper(II) Complexes and Antiglaucoma Activity Studies

“…Five peaks for 6 at d 159 (C 14 ), 138 (C 15 ), 109 (C 16 ), 112 (C 17 ) and 147 (C 18 ) could be assigned to the carbons of (HAP) + ring moiety. Four peaks for 9 at d 116 (C 13 ), 138 (C 15 ), 143 (C 16 ) and 123 (C 17 ) could be assigned to the carbons of (HBI) + ring of moiety.…”

“…[10][11][12] One of the methods used in glaucoma treatment is to reduce the production of aqueous humor 10,13 by using carbonic anhydrase inhibitors. 4,5,11,13,14 2-Aminopyridines and benzimidazoles serve as useful chelating ligands in a variety of inorganic and organometallic applications, [15][16][17] and also act as monodentate ligands which coordinate the metal ions through the nitrogen of the ring [16][17][18][19][20][21] in most cases. In addition, there are several works on 2-aminopyridine complexes in which the amino group also participates in coordination.…”

“…22,23 The chemistry of copper(II) carboxylate complexes with N-donor ligands especially with AP (2-animopyridine, 5) and BI (1H-benzimidazole, 8) has been extensively studied over the past few decades. 16,[18][19][20][21] Two types of ligands, generally acids (e.g., carboxylic acids) and bases, e.g., AP or BI, are brought together before coordination to the metal ion in order to prepare the mixed ligand complex compounds. 18,[24][25][26] The metal complexes with mixed ligands have shown better biological activities than the simple ones.…”

2-Aminopiridin Türevleri ile Sülfonamit İçeren Maleamik Asit Türevinin Proton Transfer Tuzları ve Cu(II) Komplekslerinin Sentezi, Karakterizasyonu ve İnsan Eritrosit Karbonik Anhidraz İzoenzimleri Üzerindeki Etkilerinin İncelenmesi

“…Bu komplekslerde 2-aminopiridinler çok dişli ligandlar olarak bulunmaktadır [10,[13][14][15]. 2-Aminopiridin türevleri, çoğunlukla halkanın azot atomu yoluyla metal iyonlarına tek dişli ligant [10,11,16,17] olarak bağlansa da; bazı çalışmalarda amino grubunun da yer aldığı koordinasyon halleri vardır [10,12,18].…”