Rare-earth N,N′-diarylformamidinate complexes

Can Bismuth Replace Mercury in Redox Transmetallation/Protolysis Syntheses from Free Lanthanoid Metals?

“…The main synthetic routes to highly reactive rare earth compounds, for example, organometallics, organoamides, and organo‐oxides are metathesis reactions of trivalent rare earth chlorides and divalent iodides, and protolysis reaction of rare earth bis(trimethylsilyl)amides . However syntheses from free rare earth metals offer advantages such as only one air/moisture sensitive reagent, and often simpler work up than metathesis reactions where alkali metal halide retention can be a problem .…”

“…Abstract: Tris(pentafluorophenyl)bismuth has been examined as ap otential replacement for diarylmercurials in redox transmetallation/protolysis (RTP) syntheses of reactive rare earth compounds from free rare earth metals,H gAr 2 ,a nd a proligand HL. Thus, the lanthanoid pyrazolates, [Ln(Ph 2 pz) 3 (thf) 3 ]( Ph 2 pz = 3,5-diphenylpyrazolate;L n = La, 1,Ce,2,N d,3,T b,4;t hf = tetrahydrofuran), [Ln 2 (Ph 2 pz) 4 (OMe) 2 (dme) 2 ]·2dme (Ln = Ho,5,E r,6,T m,7,L u,8;d me = 1,, [Ln(Ph 2 pz) 3 (dme) 2 ]( Ln = Dy, 9,Sm,10), [Ln(tBu 2 pz) 3 (thf) 2 ](tBu 2 pz = 3,5-di-tert-butylpyrazolate;L n= La, 11,C e, 12,S m, 13,G d, 14,D y, 15,H o, 16,T m, 17,Y b, 18,L u, 19), [Ln(ttfpz) 3 (thf) 3 ]( ttfpz = 3-(2'-thienyl)-5-(trifluoromethyl)pyrazolate;L n= La,20,S m,21), and [Er(Ph-Mepz) 3 (thf) 2 ] 22 (PhMepz = 3-phenyl- 5-methylpyrazolate) have been prepared in good yields by redox transmetallation/protolysis reactions employing lanthanoid metals and trispentafluorophenylbismuth [Bi(C 6 F 5 ) 3 ]·0.5diox (diox = 1, 4dioxane)i nd onor solvents. This is an ew and efficient synthetic route in which Bi(C 6 F 5 ) 3 replaces the commonly used Hg(C 6 F 5 ) 2 or HgPh 2 ,a nd provides proofo fc oncept for the method.…”

Potassium C–F Interactions and the Structural Consequences in N,N′-Bis(2,6-difluorophenyl)formamidinate Complexes

“…The complete polymeric network of 1 is displayed in Figure 4, showing both how the DFForm bridges across four potassium ions ( Figure 4A) and the two dimensions of the polymer ( Figure 4B,C). 5 (Ar-C(2,3,4,5,6)):4κ(F″,F′′′) manner, giving the potassium ion a coordination number of 11. Such an interesting binding mode exemplifies how the simple addition of other donors to a ligand system can dramatically alter the coordination network.…”

“…This contrasts the group one complexes of the non-fluorinated N,N′-di(aryl)formamidinate ligands [21][22][23], which readily retain coordinating solvent. Since then, we have expanded the use of fluorinated formamidinate ligands to f-block chemistry [9,16,17,[24][25][26][27][28], in a variety of different contexts [5]. One of the fluorinated formamidinate ligands used was N,N′-bis (2,6-difluorophenyl)formamidinate (DFForm) in both trivalent [16,17], and divalent [16] rare-earth complexes.…”

“…With the ability to adopt numerous coordination modes, flexible N,N -bis(aryl)formamidinates (and by extension aryl-functionalised amidinates) have earned a special place in coordination chemistry [1][2][3][4][5]. Not only does the anionic NCHN bite provide a variety of different nitrogen-based coordination modes (e.g., monodentate κ(N), bidentate κ(N,N ), or various bridging modes e.g., µ-1κ(N):2κ(N ), µ-1κ(N,N ):2κ(N,N ) to list a few) [6,7], the nitrogen-bound aromatic substituents can also provide additional coordination modes.…”