By using different transition metal containing precursors and liquid ammonia as solvent, single crystals of Sn-4(4-) cluster containing ammoniates were grown, and three new compounds have been characterized by single crystal structure determination. K4Sn4 . 8 NH3 (1) (P6(3), a=13.0370(6) angstrom and c=39.0889(11) angstrom) has been obtained by dissolving a precursor with the nominal composition "KRuSn4" in liquid ammonia, and Rb2Na2Sn4 . 4.8 NH3 (2) (Pc, a=9.4005(3) angstrom, b=15.3663(6) angstrom, c=12.7312(6) angstrom, beta=94.675(3)degrees) from a similar solution of "Rb9Na9Co16Sn24". 1 represents the last missing ammoniate of the A(4)Sn(4) compounds with heavier alkali metal cations. K-6[OH](2)[Sn-4] . 5 NH3 (3) was crystallized from solutions of the binary Zintl phase K12Sn17 in presence of AuPPh3Cl and cryptand[2.2.2] (P2(1)/c, a=10.3655(1) angstrom, b=12.7489(2) angstrom, c=16.9137(3) angstrom, beta=103.212(2)degrees), and is the Sn-4(4-) cluster compound that appears to be stable in presence of the highest amount of hydroxide so far.

Abstract C22H45K0.26N2O6Rb0.74, orthorhombic, Pbca (no. 61), a = 10.1587(8) Å, b = 16.2842(15) Å, c = 32.862(3) Å, V = 5436.2(8) Å3, Z = 8, R gt(F) = 0.0386, wR ref(F 2) = 0.0616, T = 120(2) K.

The first example of a protonated and a rare example of a metal complex of the tetrahedral tetrel cluster anion [Ge4]4− was obtained from a solution of K6Rb6Ge17 in liquid ammonia in the presence of ZnPh2 and [18]crown-6.

Experiments in liquid ammonia, originally aiming at reactions between Si containing Zintl clusters and transition metal complexes, lead to crystallization of several solvates of nine‐atomic cluster compounds. Starting with the solid Zintl compounds K12Si17, K6Rb6Si17, Rb12Si17, or K12Si8Ge9, the following compounds were crystallized: K4Si9·9 NH3 (1), K4[Si5.6Ge3.4]·9NH3 (2), K0.8Rb3.2Si9·5NH3 (3), K5Si9(OH)·8NH3 (4), K6.5Si9[H0.5N3(Si(NH2)2)3]·4.5NH3 (5), and (Rb[2.2.2]crypt)3Si9·NH3 (6). Most intriguingly, the structural characterization of [K(18‐crown‐6)]3[HSi9]·2NH3·2thf (7) and [K(18‐crown‐6)]2[H2Si4.9Ge4.1]·py (8), succeeded after dilution with tetrahydrofurane and exchange of NH3 by pyridine respectively. The different crystallization products cover bare [E9]4–, purely from Si as well as from mixed Si9–xGex composition, and partially oxidized [Si9]3– clusters, whereas compounds 7 and 8 contain the first protonated nine‐atomic Si clusters, [HSi9]3– and [H2Si4.9Ge4.1]2–. The hydrogen atoms of the protonated clusters in 7 and 8 could be located from difference Fourier maps. Besides an unharmed [Si9]4– cluster compound 5 consists of a cyclotrisilazane ring which arises from an ammonolysis reaction of one of the Si components in the solution.

C22H41N2O4Rb, monoclinic, P21/n (no. 14), a = 10.8160(9) Å, b = 17.7253(16) Å, c = 13.2179(12) Å, β = 93.961(8)°, V = 2528.0(4) Å3, Z = 4, Rgt(F) = 0.0376, wRref(F2) = 0.0694, T = 120(2) K.

The extraction of the silicide K12Si17 with liquid ammonia in the presence of a sequestering agent and AuPPh3Cl or Zn(Cp*)2 led to crystals of the solvate compound K8[Si4][Si9]·(NH3)14.6, which was characterized by single‐crystal X‐ray diffraction. It is the first compound with an isolated and ligand‐free [Si4]4– cluster obtained from solution. It also contains one [Si9]4– cluster per formula unit, whereas the precursor K12Si17 is built from [Si4]4– and [Si9]4– clusters with a 2:1 ratio.

The addition of Sn and Zn ions to [Ge9] clusters by reaction of [Ge9] 4@ with SnPh2Cl2, ZnCp*2 (Cp* = pentamethylcyclopentadienyl), or Zn2[HC(Ph2P=NPh)2]2 is reported. The resulting Snand Zn-bridged clusters [(Ge9)M(Ge9)] q@ (M = Sn, q = 4; M = Zn, q = 6) display various coordination modes. The M atoms that coordinate to the open square of a C4v-symmetric [Ge9] cluster form strong covalent multicenter M@Ge bonds, in contrast to the M atoms coordinating to triangular cluster faces. Molecular orbital analyses show that the M atoms of the Ge9M fragments coordinate to a second [Ge9] cluster with similar orbitals but in different ways. The [Ge9Sn] 2@unit donates two electrons to the triangular face of a second [Ge9] 2@ cluster with D3h symmetry, whereas [Ge9Zn] 2@acts as an electron acceptor when interacting with the triangular face of a D3h-symmetric [Ge9] 4@ unit.

AbstractThe addition of Sn and Zn ions to [Ge9] clusters by reaction of [Ge9]4− with SnPh2Cl2, ZnCp*2 (Cp*=pentamethylcyclopentadienyl), or Zn2[HC(Ph2P=NPh)2]2 is reported. The resulting Sn‐ and Zn‐bridged clusters [(Ge9)M(Ge9)]q− (M=Sn, q=4; M=Zn, q=6) display various coordination modes. The M atoms that coordinate to the open square of a C4v‐symmetric [Ge9] cluster form strong covalent multicenter M−Ge bonds, in contrast to the M atoms coordinating to triangular cluster faces. Molecular orbital analyses show that the M atoms of the Ge9M fragments coordinate to a second [Ge9] cluster with similar orbitals but in different ways. The [Ge9Sn]2−unit donates two electrons to the triangular face of a second [Ge9]2− cluster with D3h symmetry, whereas [Ge9Zn]2−acts as an electron acceptor when interacting with the triangular face of a D3h‐symmetric [Ge9]4− unit.

The addition of Sn and Zn ions to [Ge-9] clusters by reaction of [Ge-9](4-) with SnPh2Cl2, ZnCp* 2 (Cp*= pentamethylcyclopentadienyl), or Zn-2[HC(Ph2P= NPh)(2)](2) is reported. The resulting Sn-and Zn-bridged clusters [(Ge-9) M(Ge-9)](q-) (M= Sn, q= 4; M= Zn, q= 6) display various coordination modes. The M atoms that coordinate to the open square of a C-4v-symmetric [Ge-9] cluster form strong covalent multicenter M- Ge bonds, in contrast to the M atoms coordinating to triangular cluster faces. Molecular orbital analyses show that the M atoms of the Ge9M fragments coordinate to a second [Ge-9] cluster with similar orbitals but in different ways. The [Ge9Sn](2-) unit donates two electrons to the triangular face of a second [Ge-9](2-) cluster with D-3h symmetry, whereas [Ge9Zn](2-) acts as an electron acceptor when interacting with the triangular face of a D-3h-symmetric [Ge-9](4-) unit.

The Zintl phases with nominal compositions Na4Si4, Rb7NaSi8, and A12Si17 (A = K, Rb, Cs) were utilized as precursors in the synthesis of silicon nanoparticles (Si NPs). The present study characterizes and compares the yields of Si NPs synthesized from Na4Si4, Rb7NaSi8, and A12Si17 (A = K, Rb, Cs). Na4Si4 and Rb7NaSi8 Zintl phases consist of anionic silicon tetrahedra stabilized by group I cations. The A12Si17 (A = K, Rb, Cs) Zintl phases that contain [Si9](4-) and [Si4](4-) clusters have been speculated to be more soluble than the A4Si4 (A = Na, Rb, Cs) Zintl phases that contain solely [Si4](4-) clusters due to the lower charge density of the [Si9](4-) cluster. The Zintl phases were reacted with NH4Br in dimethylformamide (DMF) and subsequently capped with allylamine. The Si NPs were characterized by transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), UV-vis, and photoluminescence (PL) spectrophotometry. Furthermore, the Si yields were characterized by inductively coupled plasma mass spectrometry (ICP-MS) to evaluate if the reactions of [Si9](4-) cluster containing Zintl phases resulted in higher yields of Si NPs. The yield of Si increased with larger or mixed alkali metal Zintl phases, leading to the conclusion that Coulombic interactions between the cations and anions affect the Zintl phase's reactivity. The size of the Si NPs also increased with larger and mixed alkali metal cations, resulting in similar NP concentrations regardless of the starting material. With respect to ease of synthesis and yield, Na4Si4 remains the most practical precursor for the solution synthesis of Si NPs; however, the larger and mixed alkali metal precursors show promise for further development.

The solubility of the ternary Zintl phase K(12)Si(17-x)Ge(x) (x = 5), containing mixed group 14 element clusters, was investigated. Novel dimeric tetrahedral Zintl clusters [(η(2)-E(4))Zn(η(2)-E(4))](6-) with mixed site occupation (E = Si/Ge) were obtained through reaction with (C(6)H(6))(2)Zn in ammonia solutions and investigated by means of X-ray single crystal diffraction.