RESUMEN
The reaction of the potassium beta-diiminate KL (L = [[N(Ar)C(H)](2)CPh](-); Ar = C(6)H(3)Pr(i)(2)-2,6) with AsI(3) gave [AsI(2)L] (1), which upon reduction with KC(8) produced [(kappa(1)-L)(2)As-As[double bond, length as m-dash]As(kappa(2)-L)] (2), having a unique bent chain of the three arsenic atoms in the formal oxidation states +2, 0 and +1.
RESUMEN
The crystalline compounds [Hg{N(R)C(H)NR}(2)] (1), [Fe(L)(2)](2) (2), [Ce(L)(2)Cl](2) (3), [(AlMe(2))(3){(N(R)C(H)NC(H)N)(2)C(H)NC(H)NR}] (4), and [Ag(8)Na{(N(R)C(H)N)(2)(C(H)N)(4)R}(3)] (5) were obtained from [Li(L)](3) (A) (for 1) or [Na(L)](3) (B) and HgCl(2), FeBr(2), CeCl(3), Al(Cl)Me(2), and AgOTf, respectively [L = N(R){C(H)N}(3)R; R = SiMe(3)]. Compounds 1, 2, 3, and 5 were prepared in tetrahydrofuran (THF) at 20 degrees C; for 4, it was C(6)H(14) at -78 degrees C. NMR data for 1 showed only a single SiMe(3) environment for 1, implicating a fast exchange process. Single crystal X-ray data showed dinuclear structures for 2 and 3. Each ligand [L](-) in crystalline 2 was bound to each of the two Fe atoms in a kappa(1)- or kappa(2)-fashion, respectively, with one NSiMe(3) group of the former unattached; this was consistent with VT (1)H NMR spectral data indicative of fast exchange (at 313 K) between axial kappa(1)- and equatorial kappa(2)-N,N'-coordination to Fe. The magnetic moment for 2 in C(6)H(6) was appropriate for high-spin octahedral Fe(II). The ligands [L](-) in crystalline 3 are arranged in a helical fashion. The NMR spectra of 4 in C(6)D(5)CD(3) showed that there is an equilibrium between two asymmetric structures; minor co-products were 4', assigned as a symmetrical isomer of 4, and N(R)C(H)NR(2). The anion of 5 is proposed to be identical to that of 4'. Routes to the ligands of 1, 4, 4', and 5 are suggested; the key feature is that the ligand [L](-), unless tethered in an appropriate metal-containing matrix (as in A, B, 2, or 3), is labile because of SiMe(3) mobility, fragmentation, and/or recombination.
RESUMEN
The reaction of the potassium beta-diiminate KL (L = [{N(Ar)C(H)}(2)CPh](-); Ar = C(6)H(3)Pr(i)(2)-2,6) with PI(3) unexpectedly produced a phosphenium salt of the intermolecularly C,C-coupled ligand [P(I){N(Ar)CH}(2)C(C(6)H(4)-4)C(Ph)(CH[double bond, length as m-dash]NAr)(2)](+)[I(3)](-), while an intramolecularly N,N-coupled salt [N[upper bond 1 start](Ar)C(H)C(Ph)C(H)N[upper bond 1 end](Ar)](+)[I(5)](-) was isolated from KL + I(2).
RESUMEN
Oxidation of [Ce(NCy2)3(thf)] or [Ce(NCy2)4Li(thf)] with dry air produced the first homoleptic Ce(IV) amide [Ce(NCy2)4].
RESUMEN
Treatment of the appropriate sodium beta-diketiminate NaL or NaL' with an equivalent portion of TlCl in thf under mild conditions furnishes in good yield the first structurally characterised thallium beta-diketiminates: the monomeric, orange, crystalline Tl(I) complexes TlL and TlL' [L = {N(SiMe3)C(Ph)}2CH, L' = {N(C6H3Pr(i)(2)-2,6)C(H)}2CPh].
RESUMEN
Reactions of the silylene Si[(NCH2Bu(t))2C6H4-1,2], [Si(NN)], with NaOMe, excess Na or 1/3 Na yield the X-ray-characterised crystalline compounds [Na(micro-Si(NN)OMe)(THF)(OEt2)]2 (2b), [Na(THF)2Si(NN)]2 (3) and [Na(THF)4][(Si(NN))3-c] (4).
Asunto(s)
Aniones/química , Compuestos de Organosilicio/química , Siliconas/química , Sodio/química , Cristalización , Cristalografía por Rayos X , Espectroscopía de Resonancia por Spin del Electrón , Radicales Libres/química , Modelos Moleculares , Estructura MolecularRESUMEN
Attempted synthesis of sterically demanding bis- or tris-beta-diketiminato complexes of lanthanoids resulted in ligand deprotonation and the formation of complexes containing both a "normal" and a deprotonated ligand; one of these on protonation gave the first cationic beta-diketiminato-Ln complex.
RESUMEN
The crystalline compounds [Mg(Br)(L)(thf)].0.5Et2O [L = {N(R)C(C6H3Me2-2,6)}2SiR, R = SiMe3] (1), [Mg(L){N=C=C(C(Me)=CH)2CH2}(D)2] [D = NCC6H3Me2-2,6 (2), thf (3)] and [{Mg(L)}2{mu-OSO(CF3)O-[mu}2] (4) were prepared from (a) Si(Br)(R){C(C6H3Me2-2,6)=NR}2 and Mg for (1), (b) [Mg(SiR3)2(thf)2] and 2,6-Me2C6H3CN (5 mol for (2), 3 mol for (3)), and (c) (2) + Me3SiOS(O)2CF3 for (4); a coproduct from (c) is believed to have been the trimethylsilyl ketenimide Me3SiN=C=C{C(Me)=CH}2CH2 (5).
RESUMEN
The reaction of LiCH(TMS)2 with phenyl isocyanide PhNC has unexpectedly led to the N-lithio-indole derivative 1, that has been fully characterised including its X-ray crystal structure determination.
RESUMEN
Treatment of the beta-diketimine HL with successively LiBun and PCl2Ph gave the first C-centered monodentate beta-diketiminate PCl(Ph)L 1; with C8K 1 underwent reductive dechlorination yielding 2, a novel N-PIII-PIII-C=C heterocycle.
RESUMEN
The compounds [K((mu-N(SiMe3)C(Ph))2CH)(thf)2]infinity 1, [K(mu-N(SiMe3)C(Ph)C(H)C(Ph)NH)L]2 [L = (thf)2 2, tmen 3], [K(mu-NSi(Me)2C(Ph)C(H)C(Ph)N)(thf)3]2 4 and [K(N(H)C(Ph))2CH](thf)0.5 5 have been prepared from K[(N(SiMe3)C(Ph))2CH] and the X-ray structures of 1-4 are reported.
RESUMEN
The reaction between the lithium 3-sila-beta-diketiminate (1) and the appropriate MOBut yielded the crystalline sodium (2) or potassium (3) 3-sila-beta-diketiminate in high yield; X-ray crystal data and NMR spectra show new coordination modes for the [N(R)C(Ar)Si(R)C(Ar)N(R)]- ligand (R = SiMe3, Ar = C6H3Me(2)-2,6).
RESUMEN
The novel zwitterionic heterocycle 1 was unexpectedly obtained from the reaction between [Li(SiR3 )(thf)3 ] and ArNC. Upon heating 1 underwent an interesting ring opening to give the alkyne 2. Hence the C≡C bond effectively arises from the C-C coupling of two ArNC moieties. R=SiMe3 , Ar=2,6-Me2 C6 H3 , tmeda=N,N,N',N'-tetramethylethylenediamine.
RESUMEN
Reduction at ambient temperature of each of the lithium benzamidinates [Li(L(1))(tmeda)] or [{Li(L(2))(OEt(2))(2)}(2)] with four equivalents of lithium metal in diethyl ether or thf furnished the brown crystalline [Li(3)(L(1))(tmeda)] (1) or [Li(thf)(4)][Li(5)(L(2))(2)(OEt(2))(2)] (2), respectively. Their structures show that in each the [N(R(1))C(R(3))NR(2)](3-) moiety has the three negative charges largely localised on each of N, N' and R = Aryl); a consequence is that the "aromatic" 2,3- and 5,6-CC bonds of R(3) approximate to being double bonds. Multinuclear NMR spectra in C(6)D(6) and C(7)D(8) show that 1 and 2 exhibit dynamic behaviour. [The following abbreviations are used: L(1) = N(SiMe(3))C(Ph)N(SiMe(3)); L(2) = N(SiMe(3))C(C(6)H(4)Me-4)N(Ph); tmeda = (Me(2)NCH(2)-)(2); thf = tetrahydrofuran.] This reduction is further supported by a DFT analysis.
RESUMEN
2-Aminomethylaniline was converted into the N,N'-bis(pivaloyl) (1) or -bis(trimethylsilyl) (2) derivative, using 2 Bu(t)C(O)Cl or 2 Me(3)SiCl (≡ RCl), respectively, with 2 NEt(3), or for 2 from successively using 2 LiBu(n) and 2 RCl. N,N'-Bis(neopentyl)-2-(aminomethyl)aniline (3) was prepared by LiAlH(4) reduction of 1. From 2 or 3 and 2 LiBu(n), the appropriate dilitiodiamide {2-[{N(Li)R}C(6)H(4){CH(2)N(Li)R}(L)](2) (L absent, 4a; or L = THF, 4b) or the N,N'-bis(neopentyl) analogue (5) of 4a was prepared. Treatment of 4a with 2 Bu(t)NC, 2 (2,6-Me(2)C(6)H(3)NC) or 2 Bu(t)CN (≡ L') furnished the corresponding adduct [2-N{Li(L')R}C(6)H(4){CH(2)N(Li)R}] (4c, 4d or 4e, respectively), whereas 4b with 2 PhCN afforded [2-{N(Li)R}C(6)H(4){CH(2)C(Ph) = NLi(NCPh)}] (6). The dimeric bis(amido)stannylene [Sn{N(R)C(6)H(4)(CH(2)NR)-1,2}](2) (7) was obtained from 4a and [Sn(µ-Cl)NR(2)](2), while the N,N'-bis(neopentyl) analogue 8 of 7 was similarly derived from [Sn(µ-Cl)NR(2)](2) and 5. Reaction of two equivalents of the diamine 2 with Pb(NR(2))(2) yielded 9, the lead homologue of 7. Oxidative addition of sulfur to 7 led to the dimeric bis(diamido)tin sulfide 10. Treatment of 2 successively with 'MgBu(2)' in C(5)H(12) and THF gave [Mg{N(R)C(6)H(4)(CH(2)NR)}(THF)](2) (11a), which by displacement of its THF by an equivalent portion of Bu(t)CN or PhCN produced [Mg{N(R)C(6)H(4)(CH(2)NR)}(CNR')(n)] [R' = Bu(t), n = 1 (11b); R' = Ph, n = 2 (11c)]. The Ca (12), Sr (13) or Ba (14) analogues of the Mg compound 11a were isolated from 2 and either the appropriate compound M(NR(2))(2) (M = Ca, Sr, Ba), or successively 2 LiBu(n) and 2 M(OTos)(2). The new compounds 1-14 were characterized by microanalysis (C, H, N; not for 1, 2, 3, 5), solution NMR spectra, ν(max) (C≡N) (IR for 4c, 4d, 4e, 6, 11b, 11c), selected EI-MS peaks (for 1, 2, 3, 7, 8, 9, 10), and single crystal X-ray diffraction (for 4a, 4b, 11a).
RESUMEN
The new [Al(L(Tol))Br(2)] (1) and the known [Al(L(Ph))Me(2)] (2) were prepared as potential precursors to more novel aluminium compounds. In the event, only the latter was effective. Thus 2 and two equivalents of potassium was the source of [{Al(L(Ph))Me(2)K(2)(OEt(2))}(2)] (3). The complexes [{KSm(L(Ph))(2)}(2)] (4), [Sm(2)(L(Dph))(3)] (5) and [Sm(L(Tol,Ad))(L(Tol,Ad)-H)] (6) were obtained from SmI(2) and two equivalents of the appropriate potassium beta-diketiminate [L(Ph) or L(Tol) or L(Dph) = {N(SiMe(3))C(Ar)}(2)CH, Ar = Ph or C(6)H(4)Me-4 or C(6)H(4)Ph-4; L(Tol,Ad) = N(SiMe(3))C(C(6)H(4)Me-4)C(H)C(Ad)NSiMe(3), L(Tol,Ad)-H = N(SiMe(3))C(C(6)H(4)Me-4)C(H)C(Ad)NSiMe(2)CH(2), Ad = 1-adamantyl]. Crystalline complexes 3-6 were isolated in very low (4, 5) or satisfactory (3, 6) yield and characterised by X-ray diffraction. From comparisons of the M-N, N-C, C-C and C-C(Ar) bond lengths with suitable standards, complexes 3-5 are assigned as containing Al(3+)/(L(Ph))(3-) for 3, Sm(3+)/(L(Ph))(-)/(L(Ph))(3-) for 4, and {Sm(3+)}(2)/(L(Dph))(-)/(L(Dph))(2-)/(L(Dph))(3-) for 5. Complex 6 is best formulated as a Sm(3+) compound with one "normal" (L(Tol,Ad))(-) and one deprotonated (L(Tol,Ad)-H)(2-) ligand.
RESUMEN
Complexes [Ce(NR(2))(3)] (1) or [Ce(NR''(2))(3)] (2) were cerium(III) precursors to the X-ray characterised crystalline oligomeric oxygen-containing amidocerium(IV) compounds [{Ce(NR(2))(2)(mu-O)}(n)] (3, n = 2; 4, n = 3), [{Ce(NR''(2))(2)(mu-O)}(4)] (5), [{(R(2)N)(3)Ce}(2)(mu-[upper bond 1 start]OMOM[upper bond 1 end])] (6, M = Na; 7, M = K), [{(R(2)N)(3)CeOCe(NR(2))(2)}(2)(mu-[upper bond 1 start]OKOK[upper bond 1 end])] (8), and [{Ce(NR(2))(3)}(2)(mu-eta(2):eta(2)-O(2))].2C(n)H(2n+2) (9, n = 6; 9', n = 5) [R = SiMe(3), NR''(2) = TMP = [upper bond 1 start]NC(Me)(2)(CH(2))(3)C[upper bond 1 end]Me(2)]. Each was isolated in low, or for 5 very low, yield. Except for 4, the oxidising agent was O(2) at -27 degrees C in hexane (3, 6, 7, 8, 9), pentane (9'), or toluene (5), and a co-reagent for the alkali metal bis(trimethylsilyl)amido(oxy)cerate(iv)s was NaNR(2) (8) or KNR(2) (7, 8). From 1 and an equivalent portion of 2,6-(t)Bu(2)-benzoquinone after 5 weeks in pentane there was obtained the bis(amido)cyclotricer(IV)oxane 4. The NMR spectral solution chemical shifts for NR(2) groups of 3, 4, and 6-9 were consistent with each sample being diamagnetic and hence a Ce(IV) species. A transient amidocerium(IV) superoxide Ce(NR(2))(3)(eta(2)-O(2)) (J), or its TMP analogue, is considered to be the common first-formed intermediate in each case, while 4 is believed to have arisen from the adventitious hydrolysis of [{Ce(NR(2))(3)O}(2)((t)Bu(2)C(6)H(2)-1,4)].