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.     

Synthesis and Structural Properties of Anhydrous Rare Earth Cinnamates, [RE(cinn)3]

Anhydrous rare earth tris(cinnamates) [RE(cinn)₃] (RE = La–Lu, Y and Sc and cinnH = trans‐cinnamic acid) were prepared by metathesis in water and by direct reaction of the metal with cinnamic acid in a 1,2,4,5‐tetramethylbenzene flux at ca. 200 °C. X‐ray crystal structure determinations and X‐ray powder data show that, in the solid state, the larger lanthanoids (La–Dy) form an isomorphous polymeric series consisting of homoleptic nine‐coordinate metal centres bonded to three chelating and bridging tridentate cinnamates. The late RE^III cinnamate (RE = Dy, Ho–Lu, Y) complexes also form linear one‐dimensional polymeric chains with all RE metal atoms being seven‐coordinate. The cinnamates are either bound tridentate bridging in a μ‐η²:η¹ fashion, or μ‐η¹:η¹ syn‐syn bidentate bridging. A structural break occurs at dysprosium which has been characterised in both crystallographic forms, and gives solely the late RE form when precipitated at 80 °C. Sc^III cinnamate was also isolated as an analytically pure precipitate which was, again, found to be anhydrous in nature. A structural change was identified by powder XRD between the late RE^III cinnamates and Sc^III cinnamate.     

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(C6H4OMe-4) (C6F5): an unexpected twist

The X-ray crystal structure of Hg(C₆H₄OMe-4)(C₆F₅) reveals the first example of perpendicular rings in a diarylmercurial complex. Hg(C₆H₄OMe-4) (C₆F₅) crystallizes in monoclinic space group P2₁/c with a = 11.4004(14), b = 7.5683(9), c = 15.0247(18) Å, = 104.849 (2)° with calculated density 2.517 g cm^–3 for Z = 4.     

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).     

Lanthanoid‐Based Ionic Liquids Incorporating the Dicyanonitrosomethanide Anion

A series of low‐melting‐point salts with hexakisdicyanonitrosomethanidolanthanoidate anions has been synthesised and characterised: (C₂mim)₃[Ln(dcnm)₆] ( 1 Ln ; 1 Ln = 1 La , 1 Ce , 1 Pr , 1 Nd ), (C₂C₁mim)₃[Pr(dcnm)₆] ( 2 Pr ), (C₄C₁pyr)₃[Ce(dcnm)₆] ( 3 Ce ), (N₁₁₁₄)₃[Ln(dcnm)₆] ( 4 Ln ; 4 Ln = 4 La , 4 Ce , 4 Pr , 4 Nd , 4 Sm , 4 Gd ), and (N_1112OH)₃[Ce(dcnm)₆] ( 5 Ce ) (C₂mim=1‐ethyl‐3‐methylimidazolium, C₂C₁mim=1‐ethyl‐2,3‐dimethylimidazolium, C₄C₁py=N‐butyl‐4‐methylpyridinium, N₁₁₁₄=butyltrimethylammonium, N_1112OH=2‐(hydroxyethyl)trimethylammonium=choline). X‐ray crystallography was used to determine the structures of complexes 1 La , 2 Pr , and 5 Ce , all of which contain [Ln(dcnm)₆]^3? ions. Complexes 1 Ln and 2 Pr were all ionic liquids (ILs), with complex 3 Ce melting at 38.1 °C, the lowest melting point of any known complex containing the [Ln(dcnm)₆]^3? trianion. The ammonium‐based cations proved to be less suitable for forming ILs, with complexes 4 Sm and 4 Gd being the only salts with the N₁₁₁₄ cation to have melting points below 100 °C. The choline‐containing complex 5 Ce did not melt up to 160 °C, with the increase in melting point possibly being due to extensive hydrogen bonding, which could be inferred from the crystal structure of the complex.     

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.

     

Syntheses and structures of N-polyfluorophenyl- and N,N′-bis(polyfluorophenyl)ethane-1,2-diaminato(1- or 2-)platinum(II) complexes

The reaction of [PtX₂(L)] (X = Cl, Br, I; L = NH₂CH₂CH₂NY₂; Y = Et, Me) with thallium(I) carbonate and a polyfluorobenzene (RF) in pyridine (py) yields the platinum(II) complexes, [Pt{N(R)CH₂CH₂NY₂}X(py)] (R = C₆F₅, 4-HC₆F₄, 4-BrC₆F₄, or 4-IC₆F₄, Y = Et (1), Me (2), X = Cl, Br or I) in an improved synthesis. From the reaction of [PtCl₂(H₂NCH₂)₂)] with Tl₂CO₃ and 1,2,3,4-tetrafluorobenzene or 2-bromo-1,3,4,5-tetrafluorobenzene in py, the new complexes [Pt(NRCH₂)₂(py)₂] (3) (R = C₆H₂F₃-2,3,6 and C₆HBrF₃-2,3,5,6) have been isolated but the latter preparation also gave product(s) with a 4-bromo-2,3,5-trifluorophenyl group. From an analogous preparation in 4-ethylpyridine (etpy), [Pt(N(4-HC₆F₄)CH₂)₂(etpy)₂] (4) was obtained. The X-ray crystal structures of (3) (R = C₆HBrF₃-2,3,5,6) and (4) were determined as well as that of the previously prepared (3) (R = 4-BrC₆F₄) and a more precise structure of (3) (R = 4-HC₆F₄) has been obtained.