The steric properties of various nitrogen substituents on amidines were tuned in order to obtain group 4 mono- and bis(amidinate) dimethylamido or chloride complexes. The amidinate dimethylamido and chloride complexes were prepared, and their solid-state as well as their solution-state structures were studied. After the activation by MAO, these complexes were tested in the polymerization of propylene and ethylene. A noticeable influence of the amidine carbon and nitrogen substituents on the activity of the catalyst and properties of the obtained polymer was observed. Further, a plausible mechanism for the ethylene polymerization process is presented taking into account a combination of ESR-C60 and MALDI-TOF experiments, shedding light on the nature of the catalytic species.

Bis(amidinate) titanium and zirconium bis-(dimethylamido) complexes were prepared, and the dynamic behavior of the titanium complex containing perfluorinated amidinate ligand (11) was studied in detail. The variabletemperature NMR revealed the presence of two species in solution, in line with the different connection modes of the ligand to the metal center. The resulting complexes were tested as catalysts in the polymerization of propylene, and the resulting polymers were consistent with elastomeric high-molecularweight atactic polypropylenes.

The reactivity of the monoanionic amidinate ligand [(CH3)3CNC(Ph)NSiMe2NC(Ph)-NHC(CH3)3]Li (1) with a silyl amido side arm towards the early actinides, uranium and thorium, was investigated. While the salt metathesis reaction with ThCl4(thf)3 afforded the bis(amidinate)thorium(iv) dichloride complex [(CH3)3CNC(Ph)NSi(CH3)2NC(Ph)-NHC(CH3)3]ThCl2 (2) in high yield, the reaction of ligand 1 with UCl4 leads to a Lewis acid supported nucleophilic attack of an incoming ligand unit, yielding the trichloro uranium complex [(CH3)3CNC(Ph)Si(CH3)2-N(C(CH3)3)C(Ph)NSi(CH3)2NC(Ph)N-(C(CH3)3]UCl3 (4). The exposure of in situ formed complex 2 to wet THF solutions (<1% w of water), gave the mono(amidinate)Th(iv)(chloro)(bis-hydroxo) dimeric complex [(CH3)3CNC(Ph)NSiMe2NC(Ph)NHC(CH3)3Th(OH)2(Cl)]2·(3) as bright red needles, exhibiting extremely short Th-OH bond distances (1.741(5) Å and 1.737(5) Å). The reactivity of the thorium complex 2 in the ring opening polymerization (ROP) was studied, showing high activity. Thermodynamic and kinetic measurements were performed to shed light on the mechanism for the ROP.

The zirconium MOF NU-1000 was post-synthetically modified through solvothermal deposition to include the uranyl ion and characterized via single-crystal X-ray diffraction; photo-oxidation was also performed.

The current perspective will present the use of amidinate group 4 complexes in α-olefin polymerizations. We will present the structural studies of the complexes bearing various numbers of amidinates as spectator ligands, with a special emphasis on the bisIJamidinate) group 4 systems. The mechanistic studies elucidate the influence of various reaction conditions on the behaviour of the reactive species. Additionally, the study of the active species by techniques such as EPR spectroscopy and MALDI-TOF spectrometry are presented. We will also demonstrate how, based on such techniques, highly stereospecific bis(amidinate) titanium complexes may be designed and applied in the polymerization of propylene.

A series of titanium bis(amidinate) complexes containing pendant arms as one of the amidinate N substituents have been prepared and studied in the polymerization of propylene after their activation with MAO and other cocatalysts. The type of pendant arm greatly influences the reactivity and stereospecificity of the resulting polymers. The effect of the cocatalyst nature, its amount, and the time of the reaction have a dramatic effect on the reactivity of a titanium bis(amidinate) bis(dimethylamido) precatalyst containing a furyl group at the pendant arm.

Table of contents 1. Dynamic NMR studies ………………………………………………………….2 2. 13 C NMR spectra of the polypropylenes………………………………………15 3. Crystallographic data 3.1. Crystallographic data for ligand 5……………………………………… 17 3.2. Crystallographic data for complex 7…………………………………… 3.3. Crystallographic data for complex 8…………………………………… 3.4. Crystallographic data for complex 9…………………………………… 3.5. Crystallographic data for complex 11………………………………….. 3.6. Crystallographic data for complex 17………………………………….. 3.7. Crystallographic data for complex 18………………………………….. 3.8. Crystallographic data for complex 20………………………………….. 3.9. Crystallographic data for complex 25………………………………….. S 1 S 21178.7(6) C(2)-C(3)-C(4)-C( 5) -1.0(10) C(3)-C(4)-C(5)-C(6) 0.5(102.8( 6) C(4)-C(5)-C(6)-C(1)1.1(8) C(4)-C(5)-C(6)-C( 7)-178.4( 6) C( 1)-C( 6)-C( 7)-C( 10)-131.5( 9) C( 5)-C( 6)-C( 7)-C( 10) 48.0(10) C( 1)-C( 6)-C( 7)-C( 9) 95.4(8) C( 5)-C( 6)-C( 7)-C( 9)-85.1( 9)177.6( 5) C( 14)-N(2)-C( 13)-N(1) 3.4( 9) C( 13)-N(2)-C( 14)-C( 19)102.1( 7) C( 13)-N(2)-C(14)-C(15) -130.7(6) N(2)-C(14)-C(15)-C(16) -176.7(8) C(19)-C(14)-C(15)-C(16) -50.5(10) C(14)-C(15)-C(16)-C(17) 49.6(12) C(15)-C(16)-C(17)-C(18) -53.0(13) C(16)-C(17)-C(18)-C(19) 55.9(14) N(2)-C(14)-C(19)-C(18) 179.7(7) C(15)-C(14)-C(19)-C(18) 52.9(10) C(17)-C(18)-C(19)-C(14) S 24 S 53 N(5)-C(39) 1.446(5) N(5)-C(40) 1.458(5) N(6)-C(42) 1.468(5) N(6)-C(41) 1.476(5) C(2)-C(7) 1.388(5) C(2)-C(3) 1.385(5) C(3)-C(4) 1.384(5) C(4)-C(5)1.380(6) C( 5)-C(6)1.348( 6) C( 6)-C( 7)1.390( 5) C( 8)-C( 9) 1.402( 5) C( 8)-C( 13) 1.408(5) C( 9)-C(10) 1.394(5) C( 9)-C( 14) 1.514( 5) C( 10)-C(11)1.377( 6) C( 11)-C( 12)1.373(6) C( 12)-C( 13) 1.389(5) C( 13)-C( 17)1.514( 6) C( 14)-C( 16)1.522( 6) C( 14)-C( 15)1.526( 7) C( 17)-C( 18)1.513( 6) C( 17)-C( 19)1.515( 6) C( 21)-C( 22) 1.400( 5) C( 21)-C(26) 1.401(5) C(22)-C(23) 1.394(5) C(22)-C(27) 1.515(5) C(23)-C(24) 1.377(5) C(24)-C(25) 1.358(6) C(25)-C(26) 1.397(5) C(26)-C(30) 1.493(6) C(27)-C(28) 1.513(6) C(27)-C(29) 1.517(7) C(30)-C(31) 1.523(6) C(30)-C(32) 1.539(8) C(33)-C(34) 1.383(5) C(33)-C(38) 1.403(5) C(34)-C(35) 1.386(5) C(35)-C(36) 1.361(6) C(36)-C(37) 1.364(6) C(37)-C(38) 1.378(5) C(43)-C(44) 1.379(8) C(43)-C(45) 1.397(8) C(44)-C(45)#1 1.421(8) C(45)-C(44)#1 1.421(8) N(6)-Ti(1)-N(5) 98.35(14) S 54 C(25)-H(25C) 0.9800 C(26)-C(27) 1.529(3) S 91 C(26)-C(28) 1.537(3) C(26)-H(26) 1.0000 C(27)-H(27A) 0.9800 C(27)-H(27B) 0.9800 C(27)-H(27C) 0.9800 C(28)-H(28A) 0.9800 C(28)-H(28B) 0.9800 C(28)-H(28C) 0.9800 C(29)-H(29) 0.9500 C(30)-C(32) 1.513(4) C(30)-C(31) 1.521(4) C(30)-H(30) 1.0000 C(31)-H(31A) 0.9800 C(31)-H(31B) 0.9800 C(31)-H(31C) 0.9800 C(32)-H(32A) 0.9800 C(32)-H(32B) 0.9800 C(32)-H(32C) 0.9800 C(44)-H(44A) 0.9800 C(44)-H(44B) 0.9800 C(44)-H(44C) 0.9800 C(45)-H(45A) 0.9800 C(45)-H(45B) 0.9800 C(45)-H(45C) 0.9800 C(46)-C(48) 1.531(3) C(46)-C(47) 1.533(3) C(46)-H(46) 1.0000 C(47)-H(47A) 0.9800 S 93 C(47)-H(47B) 0.9800 C(47)-H(47C) 0.9800 C(48)-H(48A) 0.9800 C(48)-H(48B) 0.9800 C(48)-H(48C) 0.9800 C(49)-H(49) 0.9500 C(50)-C(52) 1.521(3) C(50)-C(51) 1.522(3) C(50)-H(50) 1.0000 C(5...

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