Methimazole-based ionic liquids

The alkylation reaction of 2-mercapto-1-methylimidazole 1a with iodoethane and chlorobutane produced S-alkylmethimazole halides 2a and 2b which were subjected to anion metathesis with two different metal salts (MA) to afford methimazole-based room-temperature ionic liquids 3a, 3b, and 3c in 82%, 85%, and 87% yields, respectively. S-Alkylation giving 2a and 2b suggests that methimazole reacts through the thione tautomer.     

The X-ray crystal structure of Hg(p-MeC6H4)(O2CC6F5) from synchrotron radiation

The X-ray crystal structure of Hg(p-MeC₆H₄)(O₂CC₆F₅) reveals near linear C—Hg—O units stacked into columns with intermolecular Hg–O bonding and overall distorted square-planar stereochemistry for mercury. Hg(p-MeC₆H₄)(O₂CC₆F₅) crystallizes in triclinic space group with a = 6.405(4), b = 7.285(3), c = 14.630(9) Å, = 84.07(3), = 81.21(3), = 86.87(3)° with calculated density 2.490 g cm^–3 for Z = 2.     

Steric engineering of C-F activation with lanthanoid formamidinates

Reaction of lanthanum with Hg(C6F5)2 and bulky N,N'-bis(2,6-diisopropylphenyl)formamidine (HDippForm) in tetrahydrofuran gives [LaF{DippForm}2(THF)] with a rare terminal Ln-F bond, and a high yield of a novel functionalized formamidine, DippForm((CH2)4OC6F4H-o).     

Molecular and Crystal Structures of Cp2YbX(THF) (X = Cl,Br)

Cp₂YbCl(THF) crystallizes in the orthorhombic space group Pnma (Z = 4, a = 13.109(5), b = 11.851(4), c = 9.377(3) Å, R1 = 0.0412, wR2 = 0.0482), while Cp₂YbBr(THF) is monoclinic (P2₁/n, Z = 4, a = 8.149(2), b = 12.997(2), c = 14.388(3) Å, β = 105.73(2)°, R1 = 0.0425, wR2 = 0.0436). The ligand arrangements around the formally eight coordinate Yb atoms are pseudo tetrahedral. These two determinations complete the first series of [Cp₂LnX(L)] (X = F, Cl, Br, I) structures covering all halogens for one lanthanoid and cyclopentadienyl group.     

BiPh3--a convenient synthon for heavy alkaline-earth metal amides

Environmentally friendly, commercially available BiPh(3) reacts with heavy alkaline-earth metals (Ae) and bulky trimethylsilylamines to give the corresponding amides [Ae{N(SiMe(3))(R)}(2)(thf)(n)] (R = SiMe(3), 2,4,6-Me(3)C(6)H(2), 2,6-(i)Pr(2)C(6)H(3)) in good yields, providing proof of concept for a general synthetic method.     

Cerium(III/IV) Formamidinate Chemistry,and a Stable Cerium(IV) Diolate

Four new cerium(III) formamidinate complexes comprising [Ce(p‐TolForm)₃], [Ce(DFForm)₃(thf)₂], [Ce(DFForm)₃], and [Ce(EtForm)₃] were synthesized by protonolysis reactions using [Ce{N(SiMe₃)₂}₃] and formamidines of varying functionality, namely N,N′‐bis(4‐methylphenyl)formamidine (p‐TolFormH), N,N′‐bis(2,6‐difluorophenyl)formamidine (DFFormH), and the sterically more demanding N,N′‐bis(2,6‐diethylphenyl)formamidine (EtFormH). The bimetallic cerium lithium complex [LiCe(DFForm)₄] was synthesized by treating a mixture of [Ce{N(SiHMe₂)₂}₃(thf)₂] and [Li{N(SiHMe₂)₂}] with four equivalents of DFFormH in toluene. Oxidation of the trivalent cerium(III) formamidinate complexes by trityl chloride (Ph₃CCl) caused dramatic color changes, although the cerium(IV) species appeared transient and reformed cerium(III) complexes and N′‐trityl‐N,N′‐diarylformamidines shortly after oxidation. The first structurally characterized homoleptic cerium(IV) formamidinate complex [Ce(p‐TolForm)₄] was obtained through a protonolysis reaction between [Ce{N(SiHMe₂)₂}₄] and four equivalents of p‐TolFormH. [Ce{N(SiHMe₂)₂}₄] was also treated with DFFormH and EtFormH, but the resulting cerium(IV) complexes decomposed before isolation was possible. The new cerium(IV) silylamide complex [Ce{N(SiMe₃)₂}₃(bda)_0.5]₂ (bda=1,4‐benzenediolato) was synthesized by treatment of [Ce{N(SiMe₃)₂}₃] with half an equivalent of 1,4‐benzoquinone, and showed remarkable resistance towards protonolysis or reduction.     

Metal‐Promoted Nucleophilic Addition and Cyclization of Diamines with Dicyanonitrosomethanide, [C(CN)2(NO)]−

Additional cyclization : Dicyanonitrosomethanide, [C(CN)₂(NO)]^? undergoes nucleophilic addition and cyclization of 1,2‐diaminoethane and 1,3‐diaminopropane on the nitrile groups to form imidazolinyl and 1,4,5,6‐tetrahydropyrimidinyl groups, respectively. Ethanolamine has lower reactivity and fails to cyclize.