Marta E. G. Mosquera

Syntheses and magnetic properties of hexanuclear [Cp2Mn3(L1)4]2 and octanuclear [Mn8(L2)12(μ4-O)2] (L1 = 2-HNC5H5N, L2 = 2-NH-3-Br-5-MeC5H3N, Cp = C5H5)

The reactions of manganocene, Cp2Mn, with 2-aminopyridine (L1H) or 2-amino-3-bromo-5-methylpyridine (L2H) give the novel hexanuclear and octanuclear Mn(II) amido cage compounds [Cp2Mn3(L1)4]2 (1) and [Mn8(L2)12(mu 4-O)2] (2); magnetic measurements on which provide a rare insight into the magnetic properties of amido-bridged metal clusters.

Synthesis and structure of [{Sn(μ‒PCy)}3(Na·PMDETA)2], containing an electron-deficient [{Sn(μ‒PCy)}3]2- dianion

The reaction of CyPHNa with Sn(NMe2)2 in the presence of PMDETA (= n{Me2NCH2CH2}2NMe) gives the title compound [{Sn(μ–PCy)}3(Na·PMDETA)2] n(1), containing an electron-deficient [(Sn(μ–PCy)}]32− dianion with a novel two-electron, three centre (2e–3c) bonding arrangement.

A study of the reactivity of trans-[RuCl2(dppm)2] toward isocyanides

The treatment of trans-[RuCl2(dppm)2] with isocyanides in different reaction conditions affords trans-[RuCl(CNR)(dppm)2Cl (3a: Rue5f8 1Bu, 3b: Rue5f8Ph), trans-[RuCl(CNR)(dppm)2]PF6 (4a and 4b), trans-[RuCl(CNR)2(dppm)(dppm)-P]PF6 (6a and 6b), and trans-(Ru(CNR)2(dppm)2(PF6)2 (7a and 7b). During the course of these reactions several intermediates resulting from ring-opening and -closing processes of the dppm ligands were spectroscopically characterized. Finally, 6a was selectively oxidized with H2O2 to give trans-[RuCl(CNR)2(dppm)(dppmO-P)]PF6 (8) which wad transformed to trans-[RuCl(CNR)2(dppm)(dppmO)](PF6)2 (9) by treatment with TIPF6.

Applications of manganocene in the synthesis of Mn(II) amide and imide cages

The reactions of manganocene, Cp2Mn (Cp = C5H5), with 2-aminopyrimidines give similar, octameric amido/imido cage complexes of general formulae [{CpMnNHR}{MnNR}]4 n[R = 4,6-Me2pm (1a), 4-MeO-6-Mepm (1b), 4,6-(MeO)2pm (1c); pm = pyrimidinyl]. The structures of these complexes can be visualised as being composed of central Mn4N4 imido cubane units that are coordinated at their peripheries by four [CpMnNHpm] monomers. In contrast, less acidic 2-aminopyridine (2-NH2py) and 8-aminoquinoline (8-NH2quin) are only singly deprotonated under similar conditions, giving the unusual hexanuclear amido complex [Cp2Mn3(NHpy)4]2 n(2) and the dimer [CpMn(μ-8-HNquin)]2 n(3). N,N′-Dibenzylethylenediamine [(BnNHCH2)2] only forms the simple adduct [(η1-Cp)(η5-Cp)Mn{(BnNHCH2)2}] n(4) n(Bn = CH2Ph) with Cp2Mn, in which no deprotonation of the organic acid has occurred. The X-ray structures of the new complexes 1b–c, 3 and 4 are reported (1a and 2 having been communicated previously).

Association and fragmentation of imidotin(II) complexes containing donor-functionalised peripheries; towards new three-dimensional main group metal ligands

Structural studies of a series of tin(II) imido cubanes, [SnNR]4, containing donor-functionalised organic substituents (R), have allowed the systematic investigation of the factors controlling and affecting association of these architypal tin(II) complexes in the solid state. In addition to steric shielding of the Sn4N4 cores, intra- and inter-molecular O and N donation modifies or curtails association via Sn⋯Sn interactions, and can even facilitate fragmentation of the cubane cores.

Nucleophilic addition to a Sn(II) imido cubane, [SnNR]4; a new route to heteroleptic stannates

Nucleophilic addition to Sn(II) imido cubanes provides a novel route to heteroleptic stannates, as exemplified by the formation of [{Sn(NHmmp)(OtBu)2}K·thf]2 (2) and [{Sn(MeNCH2CH2NMe)(NHmmp)}Li]∞ (3) from the in situ reactions of the imido Sn(II) cubane [Sn(Nmmp)]4 (1) (mmp = 2-MeO-6-MeC6H3) with tBuOK and [MeN(Li)CH2CH2(Li)NMe]. This pathway demonstrates that Sn(II) imido cubanes can act as synthons for their aza-stannylene constituents, RNSn:.

Effects of meta-substitution on aggregation in the cubanes [SnNR]4{R = [2-Me-5-MeOC6H3], [2,5-(MeO)2C6H3] and [3,5-(MeO)2C6H3]}

An investigation of the solid-state X-ray structures of the cubanes [SnN{2-Me-5-MeOC6H3}]4, (1), [SnN{2,5-(MeO)2C6H3}]4, (2), and [SnN{3,5-(MeO)2C6H3}]4, (3), containing meta-MeO substituents on their aromatic groups, shows that unprecedented modes of intra- and intermolecular association occur. In 1, novel co-ordination of two of the cubane Sn2N2 faces by thf ligands is found, the first observation of Lewis base solvation by a separate donor ligand in this class of complexes. In 2, dimerisation of cubane units occurs via a combination of Sn⋯Sn, Sn⋯O and arene⋯Sn ninteractions, whereas in 3, an unusual ‘sinusoidal’ pattern of aggregation is seen.

Synthesis and structure of [{Sn4(NBut)3P}{Sn4(NBut)3(OSiMe3)}]; a low-oxidation state p-block metal complex containing a P3− anion

The complex n[{Sn4(NBut)3P}{Sn4 n(NBut)3(OSiMe3)}] 1 is the nfirst example of a low-oxdation state p-block metal complex containing a nP3− anion.