The synthesis and structural characterisation of 2-arsa- and 2-stiba-1,3-dionato complexes of s- and p-block elements

Abstract

The syntheses and structural characterisations of a number of 2-arsa-and 2-stiba-1,3-dionato complexes of main group elements are reported. The synthetic methods that were employed in this study include the reaction of lithium heterodionate complexes, [Li{Z 2 -O,O-OC(R)EC(R)O}], E ¼ As or Sb, R ¼ alkyl or aryl, with main group metal halides or the reactions of arsa-and stiba-enols, O=C(R)E=C(R)OH, with either main group alkyl or amide complexes. The hetero-ligands in the prepared complexes have been shown by X-ray crystallographic studies to coordinate the main group metal centre in several modes, that is, in a delocalised form (Z 2 -O,O coordination) as in [{M[Z 2 -O,O-OC(R)EC(R)O](L)} 2 ], M ¼ Li or Na, E ¼ As or Sb, R ¼ Ad (adamantyl) or Ph, L ¼ Et 2 O or DME; [Na{Z 2 -O,O-OC(Mes*)EC(Mes*)O}(DME) 2 ], E ¼ As or Sb, Mes* ¼ C 6 H 2 Bu t 3 -2,4,6, and [Mg{Z 2 -O,O-OC(Ph)AsC(Ph)O} 2 (DME)]; in a localised diacylpnictido form (Z 1 -E coordination) as in P[As{C(O)R} 2 ] 3 , R ¼ But or Ph; or as a combination of the two modes (Z 1 -E-: Z 2 -O,O-) as in [LiCl(Et 2 O)(DME){Z 2 -O,O-Cl 3 InAs[C(O)R] 2 }].

Formation of a Ce(IV) Oxo Complex via Inner Sphere Nitrate Reduction

“…The oxo ligand in 1 is also coordinated by the Li + ion of the [Li­(12-crown-4)] + moiety. The Li–O bond length is 1.827(6) Å, which is within the range of those exhibited by Li + cations bound by an organic carbonyl. − Finally, it is interesting to note the similarity between the capping [Li­(12-crown-4)] cation in 1 and the capping [K­(18-crown-6)] moiety found in [K­(18-crown-6)]­[M­(E)­(NR 2 ) 3 ] (M = Th, U; E = O, S, Se, Te; R = SiMe 3 ), − which can be viewed as its actinide analogues.…”

Building Chains – Three Different Pnictogen Atoms in an Entirely tert‐Butyl Substituted Molecule

“…The As–P bond lengths of 233.7(2) and 234.4(2) pm are in the range of those in 7 and the ionic compounds [(Ph 3 As) 2 PMe][AlCl 4 ] 2 and [(Me 3 As) 2 PMe][F 3 CSO 3 ] 2 , . In the neutral triarsaphosphanes P[As{C(O)R} 2 ] 3 (R = t Bu, Ph) As–P bond lengths that are shorter by 3 pm and smaller As–P–As angles are observed , …”

“…An all‐ trans configuration of the substituents is observed in the four‐membered As 2 P 2 ring compounds [{Cp*(CO) 2 FeAs} 2 (MesP) 2 ] and [( t BuPh 2 SiP) 2 {(Me 3 Si) 2 CHAs} 2 ] , . Radial triarsaphosphanes P[As{C(O)R} 2 ] 3 (R = t Bu, Ph), synthesized by Jones et al, bear three phenyl‐ or tert ‐butyl‐diacylarsenido substituents on the phosphorus atom , . Cationic As–P compounds were described by Burford et al For example, the cations [R 3 AsP(Me)AsR 3 ] 2+ (R = Me, Ph) were obtained from reactions of chlorophosphanes with tertiary arsanes and chloride‐abstracting agents , …”

Metalated Oligosilanylstibines

“…Reaction of (Me 3 Si) 3 Sb with MeLi provides convenient access to the stibide, which was shown to be extremely useful for the synthesis of a number of interesting compounds. 3 − 10 The analogous potassium stibide (Me 3 Si) 2 SbK was obtained by reaction of (Me 3 Si) 3 Sb with potassium tert -butoxide. 11…”