Physical Sciences and Mathematics Commons^™

Isomerization And Chelation Studies Of Dangling Phosphine Complexes Of Group 6, Zhongjiang Jia

Masters Theses

Vinyl addition reactions, catalyzed by 2,2'-azobis(isobutyronitrile) (AIBN), have been used to prepare six pentacarbonyl complexes of group 6, each of which contains a dangling Ph₂PCH₂CH₂P(p-tol)₂ ligand.

Each of the six complexes undergoes slow isomerizationand chelation at 55 °C in perdeuterated toluene:

The reactions were monitored by ³¹P{¹H} NMR spectroscopy. The isomerization reactions are reversible in solution, while the chelated products form irreversibly with the loss of carbon monoxide. The rate constants, K₁ and K_-1, have been determined for the three pairs of linkage isomers. Equilibrium …

The Synthesis And Characterization Of Novel 5,6-Disubstituted 1,10-Phenanthrolines, Liansheng Zeng

Masters Theses

Two new ligands, 5-amino-6-nitro-1,10-phenanthroline (5-NH₂-6-NO₂-phen), produced by amination of 5-NO₂-1,10-phenanthroline, and 5,6-diamino-1,10-phenanthroline (5,6-(NH₂) ₂-phen) ,produced by reduction of 5-NH₂-6-NO₂-phen, have been synthesized and characterized. The ligand 5-NH₂-6-NO₂-phen has been coordinated to a Ru(II) metal center to produce the Ru(II)-polypyridine complex [ (bpy) ₂Ru (5-NH₂-6-NO₂-phen)] (PF₆ ) ₂ (bpy= 2, 2' -bipyridine) . This complex has been characterized by IR, UV-Vis, ¹H-NMR, and cyclic voltammetry (CV) .

The Synthesis And Characterization Of [Ruii (Bpy) 2 (Biphen) ] (Pf6)2 And [ (Bpy) 2ruii (Biphen) Ruii (Bpy) 2] (Pf6)4, Mei-Yueh Chang

Masters Theses

A new bidentate polypyridine bridging ligand (biphen), produced by the condensation of 1,10-phenanthroline-5,6-dione with 5,6-diamino-phenanthroline has been synthesized and characterized. In addition the monometallic complex [(bpy)₂Ru^II(biphen)](PF₆)₂ and the bimetallic complex [(bpy)₂Ru^II(biphen)Ru^II(bpy)₂](PF₆)₄ have been prepared. The complexes were characterized by elemental analysis, by ¹H-NMR spectroscopy and by cyclic voltsmmetry(CV).

The results of these analyses seem to indicate that biphen acts like two independent units when attached to a - Ru^II(bpy)₂ fragment. a bipyridine portion and a phenazine portion. Moreover, …

Novel Compounds (Including Transition-Metal Complexes) Based On 1,10-Phenanthroline-5,6-Dione, Hui Zhou

Masters Theses

This thesis describes the synthesis of the transition metal complex [(bpy) ₂Os^II (pptd)] (PF₆)₂^·2H₂O, an analog of [(bpy) ₂Ru^II (pptd)] (PF₆)₂^·2H₂O. Spectroscopic and electrochemical data on this complex are reported here. It was found that the electronic communication between the metal center and the pteridinedione portion of pptd did not appear to be enhanced in the Os(II) complex relative to its Ru(II) analog. The increased ability of Os(II) to undergo backbonding appeared to affect only the 1,10-phenanthroline portion of pptd.

A useful …

Equilibrium And Kinetic Studies Of Isomerization Of (Oc)5m[Η1-Pph2ch2ch(Pph2)2] And (Oc)5m[Η1-Pph2ch(Pph2)Ch2pph2] (M=Cr, Mo, W), Weiying Lin

Masters Theses

It has been found that (OC)₅M[η¹-PPh₂CH₂CH(PPh₂)₂] and (OC)₅M[η¹-PPh₂CH(PPh₂)CH₂PPh₂] (M=Cr, Mo, W) exist in equilibrium in solution. This linkage isomerization is the first experimental evidence for the exchange of terminal and coordinated phosphorus groups in pentacarbonyl complexes of group 6 metals.

(OC)₅M[η¹-PPh₂CH₂CH(PPh₂)₂] ⇌ (OC)₅M[η¹-PPh₂CH(PPh₂)CH₂PPh₂]

(M = Cr, Mo, W)

In this work, equilibrium …

The Synthesis Of N-Chlorosulfonyl Β-Lactams And Their Rearrangements, Lihua Zhang

Masters Theses

The synthesis of several N-chlorosulfonyl-β-lactams and their rearrangements have been carried out via CSI (chlorosulfonylisocyanate) reaction. The mechanism of β-lactam synthesis as well as its rearrangements were also studied. The characterization of β-lactams was performed with IR, ¹H and ¹³C NMR, and HRMS. β-lactams 2-chlorosulfonyl-1-methyl-2-azabicyclo[4.2.0]octan-3-one (71), 1-chlorosulfonyl-4-methyl-4- (phenylmethyl)azetidin-2-one (74) and 1-chlorosulfonyl-4,4- (diphenylmethyl)azetidin-2-one (75) were synthesized for the first time. β-lactam 4-chlorosulfonyl-3, 9, 9-trimethyl-4-azatricyclo [6.1.0.0^3,6] nonan-5-one (73) was obtained as crystalline solid instead of liquid.

Different effects, such as temperature, solvents and catalysts, on the rearrangement of the …