K(4)Sn(9) dissolves in ethylenediamine (en) to give equilibrium mixtures of the diamagnetic HSn(9)(3-) ion along with K(x)Sn(9)((4-x)-) ion pairs, where x = 0, 1, 2, 3. The HSn(9)(3-) cluster is formed from the deprotonation of the en solvent and is the conjugate acid of Sn(9)(4-). DFT studies show that the structure is quite similar to the known isoelectronic RSn(9)(3-) ions (e.g., R = i-Pr). The hydrogen atom of HSn(9)(3-) (δ = 6.18 ppm) rapidly migrates among all nine Sn atoms in an intramolecular fashion; the Sn(9) core is also highly dynamic on the NMR time scale. The HSn(9)(3-) cluster reacts with Ni(cod)(2) to give the Ni@HSn(9)(3-) ion containing a hydridic hydrogen (δ = -28.3 ppm) that also scrambles across the Sn(9) cluster. The Sn(9)(4-) ion competes effectively with 2,2,2-crypt for binding K(+) in en solutions, and the pK(a) of HSn(9)(3-) is similar to that of en (i.e., Sn(9)(4-) is a very strong Brønsted base with a pK(b) comparable to that of the NH(2)CH(2)CH(2)NH(-) anion). Competition studies show that the HSn(9)(3-) ⇄ Sn(9)(4-) + H(+) equilibrium is fully reversible. The HSn(9)(3-) anion is present in significant concentrations in en solutions containing 2,2,2-crypt, yet it has gone undetected for over 30 years.

Controlled I 2 oxidations of preformed Zintl clusters [Pt 2 Sn 9 (PPh 3 )] 2and [Sn 9 Ir(cod)] 3-, give well ordered tin-rich intermetallic nanoparticles (NPs) of PtSn 4 and Ir 3 Sn 7, respectively. The intermetallics were characterized by HR-TEM and XRD analysis. Both clusters have strong structural similarities with the final intermetallic, which appears to be an important factor in determining the phase of the resulting intermetallic NP. Despite the 1:9 (Ir:Sn) atomic ratio of the [Sn 9 Ir(cod)] 3cluster, ordered Ir 3 Sn 7 NPs were formed instead of the compositionally-similar IrSn 4 phases. PtSn 4 is difficult to prepare and isolate due to the formation of other known Pt-Sn phases, such as PtSn, PtSn 2 and Pt 3 Sn. This paper is dedicated to Prof. Malcolm Chisholm (friend, colleague and mentor extraordinaire) on the occasion of his 70 th birthday.

The icosahedral [M@Pb 12 ] 3À (M = Co(1), Rh(2), Ir(3)) cluster ions were prepared from K 4 Pb 9 and Co(dppe)Cl 2 (dppe = 1,2-bis(diphenylphosphino)ethane)/[Rh(PPh 3 ) 3 Cl]/[Ir-(cod)Cl] 2 (cod = 1,5-cyclooctadiene), respectively,i nt he presence of 18-crown-6/ 2,2,2-cryptand in ethylenediamine/toluene solvent mixtures. The [K(2,2,2-cryptand)] + salt of 1 and the [K(18-crown-6)] + salt of 3 were characterized via X-ray crystallography; the ions 1 and 3 are isostructural and isoelectronic to the [Rh@Pb 12 ] 3À (2)i on as well as to the group 10 clusters [M'@Pb 12 ] 2À (M' = Ni, Pd, Pt). The ions are all 26-electron clusters with nearp erfect icosahedral I h point symmetry.C lusters 1-3 show record downfield 207 Pb NMR chemicals hifts duet os-aromaticity of the cluster framework. Calculated and observed 207 Pb NMR chemical shifts and 207 Pb-x M J-couplings ( x M = 59 Co, 103 Rh, 193 Ir) are in excellent agreement and DFT analysis shows that the variations of 207 Pb NMR chemical shifts for the [M@Pb 12 ] 2, 3À ions (M = Co, Rh, Ir,N i, Pd, Pt) are mainly governed by the perpendicularly oriented s 11 component of the chemical shift anisotropy tensor. The laser desorption ionization time-of-flight (LDI-TOF) mass spectra contain the molecular ions as well as several new gas phase clusters derived from the parents. The DFT-minimized structures of these ions are described.[a] Dr.

The closo- [E 9 Ir(cod)]3-ions where E = Sn (1), Pb (2) (cod = 1,5-cyclooctadiene) were prepared from precursors [Ir(cod)-Cl] 2 , K 4 E 9 , and 2,2,2-cryptand in ethylenediamine/toluene solvent mixtures. The [K(2,2,2-crypt)] + salts were isolated and characterized by NMR spectroscopy and single-crystal X-ray diffraction. The clusters are the first known Ir I Zintl

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