Synthesis of the First Lanthanoid(II) Pyrazolate Complex by Redox Transmetallation from Thallium and Mercury Reagents

Synthesis and Characterization of Calcium Complexes Containing η2-Pyrazolato Ligands

“…Given the larger size of the calcium ion, it is perhaps not surprising that the η 2 -pyrazolato ligand bonding mode is observed exclusively in 1 − 9 . η 2 -Pyrazolato ligands are very common in lanthanide pyrazolato complexes because of the ionic bonding and large sizes of these ions. − Since the groups 1−3 metal ions exhibit predominant ionic bonding and since the sizes of many of these ions are as large or larger than the lanthanide ions, η 2 -pyrazolato ligand coordination should be frequently observed in pyrazolato complexes of the main group metals. We are particularly interested in η 2 -pyrazolato ligand coordination, since the steric profile of the η 2 -pyrazolato ligand should be similar to that of appropriately substituted 1,3-diketonate ligands.…”

Rare Earth Starting Materials and Methodologies for Synthetic Chemistry

“… 35 Interestingly, direct protonolysis between Yb(C 6 F 5 ) 2 and Ph 2 pzH proceeds smoothly to give Yb(Ph 2 pz) 2 ( 75 Ph2 -Yb ). 174 The use of RTP reactions is exemplified by the extensive work done by Junk, Deacon, and co-workers in the synthesis of RE formamidinate (ArForm; Ar = Dipp, p -Tol, o -(CF 3 )C 6 H 4 , DF, 2,3,4,5-F 4 C 6 H – TF, o -FC 6 H 4 – F) complexes ( Scheme 29 ). 160 , 186 , 188 − 191 , 211 For these ligand systems, reactivity conditions and stoichiometries can be tailored to obtain either divalent or trivalent formamidinate complexes, “RE(ArForm) 2 ” ( 76 Ar -RE ) and “RE(ArForm) 3 ” ( 77 Ar -RE ), irrespective of the choice of organomercurial agent, although Hg(C 6 F 5 ) 2 is usually the oxidant of choice.…”

“…Such species are typically transmetalating reagents, with organomercurials as the most popular choices ( e.g. , HgPh 2 , Hg­(C 6 F 5 ) 2 , and Hg­(CCPh) 2 ); ,,− however, these methodologies have also been extended to include other redox active metals, such as Sn, ,, Tl, ,− Bi, , and Ag . The first reaction of an RE with an organomercurial reagent was reported in 1945 by Gilman and Jones, who reacted La metal with HgPh 2 though they were not able to identify the reactivity products .…”

Synthesis, Structure, and Molecular Orbital Studies of Yttrium, Erbium, and Lutetium Complexes Bearing η2-Pyrazolato Ligands: Development of a New Class of Precursors for Doping Semiconductors

“…With these considerations in mind, we report the synthesis, structure, and properties of a series of lanthanide complexes bearing η 2 -pyrazolato ligands and neutral nitrogen donors. Deacon and co-workers have reported extensive studies of lanthanide complexes bearing η 2 -pyrazolato ligands and neutral oxygen donors. − However, Deacon's compounds may be unsuitable for use in group 13 compound semiconductor matrixes due to the oxygen content and because the complexes apparently decompose with loss of the neutral oxygen donor ligands upon attempted sublimation. , By contrast, the lanthanide complexes described herein sublime without decomposition and are thermally stable to nearly 300 °C. Furthermore, molecular orbital calculations have been carried out on model yttrium complexes, and provide detailed insight into the bonding between lanthanide metal centers and pyrazolate donors.…”