Sr5[NbN4]N ‐ A Nitridoniobate(V) Nitride Containing Isolated [NbN4]7‐ Tetrahedra and Octahedral Chains 1(Sr4Sr2/2N7+)

Sr₅[NbN₄]N (transparent, red single crystals) was synthesized by reaction of Sr2N with Nb under nitrogen at ambient pressure and 1223 K. The crystal structure was solved and refined in the space group Pbcm (no. 57), Z = 4, with lattice constants a = 646.6(3) pm, b = 1792.5(9) pm, c = 729.8(4) pm, and R = 0.019, wR² = 0.034. The crystal structure contains both isolated tetrahedra [NbN₄]^7‐ as well as chains of corner sharing octahedra 1(Sr₄Sr_2/2N⁷⁺). Strontium is irregularly coordinated by nitrogen (CN = 4 ‐ 6, Sr‐N: 252.3(4) ‐ 340.8(3) pm); nitrogen is located in a distorted octahedral environment by strontium and niobium (Nb‐N: 194.5(4) ‐ 199.2(2) pm). By formal reduction of the structural building units to their centers a close structural relationship to both the NiAs and the CaSi type structure is evident.     

Transitions Between Lanthanum Cuprates: Crystal Structures of T′, Orthorhombic,and K2NiF4‐type La2CuO4

Through low‐temperature synthesis in CsOH flux, lanthanum cuprate La₂CuO₄ can be obtained in a metastable form, the so‐called T′ modification (tetragonal, I4/mmm, no. 139, a = 400.95(2) pm, c = 1254.08(7) pm). When heated, this T′ phase transforms into a K₂NiF₄‐type modification, whose crystal structure was now refined from X‐ray powder data (tetragonal, I4/mmm, no. 139, a = 383.29(3) pm, c = 1331.3(2) pm at T = 1073 K). The well‐known orthorhombic phase (s.g. Cmce, no. 64, a = 536.14(3) pm, b = 1315.53(8) pm, c = 540.20(3) pm) – usually obtained via conventional solid state synthesis – was observed to form upon cooling from the K₂NiF₄‐type modification. High‐temperature powder diffractometry allowed crystal structure refinements for all of the three phases.     

Darstellung,Kristallstruktur und Eigenschaften von KLi2As

Preparation, Crystal Structure, and Properties of KLi₂As The novel arsenide KLi₂As has been synthesized either from the elements or from mixtures of the binary components Li₃As and K₃As in sealed Nb ampoules at 823 K and 623 K, respectively. It crystallizes in the space group Pmmn (no. 59) with a = 445.8(9); b = 671.5(11); c = 627.0(12) pm and Z = 2 formula units. The metallic reflecting silvercoloured platelets hydrolize rapidly under wet air. The compound (Pearson code oP8) is isopuntal with BaLi₂Si and an intermediate between the Li₃N and the Na₃As type of structure. Potassium is distorted tetrahedrally coordinated by four As atoms (d(K? As) = 355 and 367 pm), arsenic by four potassium and six lithium atoms (d(As? K) = 355–367 pm; d(As? Li) = 260–265 pm) in form of a sphenocorona. Lithium is threefold coordinated (distorted trigonal planar) by arsenic and this unit is enveloped by a monocapped trigonal prism build by three lithium and four potassium atoms.     

Darstellung und Kristallstruktur von K4[SnO3]

Preparation and Crystal Structure of K₄[SnO₃] K₄[SnO₃] crystallizes with the K₄[PbO₃] structure in the orthorhombic spacegroup Pbca (No. 61) with the lattice constants a = 652.2(3) pm, b = 1 112.1(5) pm and c = 1 893.7(7) pm. In the structure isolated ψ-tetrahedral anions [Sn^IIO₃]^4? are arranged in layers perpendicular [001]. The structure of K₄[SnO₃] will be compared with those of stannates and plumbates of composition A₄[M^IIO₃] (A = Na, K, Rb, Cs) and with the known potassium stannates(II).     

Synthese und Kristallstruktur von [KNPPh3]6 · 4 C7H8

Synthesis and Crystal Structure of [KNPPh₃]₆ · 4 C₇H₈ [KNPPh₃]₆ · 4 C₇H₈ ( 1 ) has been prepared from HNPPh₃ and potassium hydride in boiling toluene forming pale yellow moisture sensitive crystals, which were characterized by a crystal structure determination. Space group P1, Z = 2, lattice dimensions at –83 °C: a = 1517.9(2), b = 1894.0(2), c = 2150,4(2) pm, α = 84.39(1)°, b = 89.31(1)°, c = 89.97(1)°, R₁ = 0.0684. 1 forms a K₆N₆ skeleton of a double cube with a common face of two K and two N atoms, the latter being fivefold coordinated by four K atoms and the P atom of the PPh₃ groups.     

Die Kristallstruktur von K[F5W(≡NCl)]

Crystal Structure of K[F₅W(≡NCl)] Orange single crystals of K[F₅W(≡NCl)] have been formed as a by‐product from the reaction of tungsten nitrido chloride, WNCl₃, with Me₃SnF in the presence of potassium fluoride in toluene suspension. K[F₅W(≡NCl)] crystallizes in the monoclinic space group P2₁/c with four formula units per unit cell. Lattice dimensions at –83 °C: a = 1145.9(3), b = 770.4(2), c = 772.5(2) pm, β = 99.91(1)°, R₁ = 0.0742. The compound forms an ionic structure with octahedral [F₅W(≡NCl)]^– ions with a nearly linear arrangement of the N‐chloroimido ligand group W≡N–Cl (bond angle 173°, WN distance 174 pm). The K⁺ ions link the anions via K…F contacts and coordination number eight to form double layers along [100]. The layers itself are associated by short bounding Cl…F contacts of 279 pm.     

Einkristallstrukturuntersuchungen an hexagonalen Fluorperowskiten AMIIF3 (MII = Mg,Mn, Fe,Co, Ni)

Single Crystal Structural Studies at Hexagonal Fluoride Perovskites AM^IIF₃ (M^II = Mg, Mn, Fe, Co, Ni) At single crystals of nine fluoride phases AMF₃ the hexagonal perovskite structures were refined by X‐ray methods, of RbNiF₃ below T_C £ 145 K, too. The hexagonal 6 L type (P6₃/mmc, Z = 6) is found at: RbMgF₃ (a = 585.7(1); c = 1426.0(1) pm), CsMnF₃ (624.4(1); 1515.4(4) pm), CsFeF₃ (616.8(1); 1488.4(6) pm), Rb_0.63Cs_0.37CoF₃ (599.1(1); 1460.3(4) pm), RbNiF₃ (128 K: 582.6(1); 1426.4(6) pm), Cs₂BaLiNi₂F₉ (593.1(1); 1447.1(4) pm). Of the hexagonal‐rhombohedral 9 L type (R 3 m, Z = 9) are CsCoF₃ (620.1(1); 2264.0(7) pm) and yellow CsNiF₃ (614.7(1); 2235.3(6) pm), prepared at lower temperatures resp. under high pressure, whereas light green CsNiF₃ (625.5(1); 524.2(1) pm) belongs to the 2 L type (P6₃/mmc, Z = 2). The occurence of these structures and the interatomic distances observed, comparing also normal and high pressure phases, are discussed in connection with the tolerance factor.     

The Single Crystal Structures of the Copper Usovites Ba2CaCuV2F14 and Ba2CaCuCr2F14

The results of single crystal X‐ray structure determinations are reported for Ba₂CaCuV₂F₁₄ (a = 1383.6(3), b = 540.89(8), c = 1493.1(3) pm, β = 91.65(3)°) and Ba₂CaCuCr₂F₁₄ (a = 1381.1(5), b = 535.5(1), c = 1481.4(6) pm, β = 91,50(4)°), both isotypic with usovite (space group C2/c, Z = 4). The resulting average distances are V‐F: 193.8 pm, Cr‐F: 190.7 pm, and Cu‐F: 209.2 resp. 207.1 pm for the Jahn‐Teller elongated [CuF₆] octahedra. Within the cross‐linked double chains of octahedra F‐bridged trimers M‐Cu‐M, magnetically studied earlier, are confirmed and discussed.     

Electronic Conditions of Diatomic (BN) Anions in the Structure of CaNiBN

CaNiBN was synthesized from Ca, Ni and BN in sealed tantalum containers at 1000 °C. The structure was determined by single‐crystal X‐ray diffraction (P4/nmm, Z = 2, a = 353.24(3) pm, c = 763.59(9) pm, R₁ = 0.019, wR₂ = 0.045 for all collected independent reflections). CaPdBN was synthesized after the same method, and a powder pattern was indexed isotypically (P4/nmm, a = 377.38(1) pm, c = 760.95(4) pm). The CaNiBN structure contains (BN) units with B—N bond lengths of 138.1(4) pm. If the (BN) unit in CaMBN (M = Ni, Pd) is replaced by (C₂), the structure can be considered as being isotypic with the structure of UCoC₂. Crystals of CaNiBN exhibit metallic lustre. According to the calculated band structure an extremely narrow band gap is present. The covalency between Ni and BN is marked by two important σ type interactions. A third type of interaction between (BN) π* and Ni orbitals represents the slightly occupied conduction bands. CaNiBN exhibits temperature independent paramagnetism and no superconducting transition down to 4 K.     

Über Fluoridsulfide (MFS) der Lanthanide (M = La–Nd,Sm, Gd–Lu) im A‐Typ mit PbFCl‐Struktur

On Fluoride Sulfides (MFS) of the Lanthanides (M = La–Nd, Sm, Gd–Lu) with A‐ or PbFCl‐Type Crystal Structure By the reaction of the elemental lanthanides (M = La–Nd, Sm–Lu) with the respective trifluorides (MF₃) and sulfur (S) in 2 : 1 : 3‐molar ratios at 850 °C, single‐phase fluoride sulfides of the composition MFS can be obtained in evacuated, gas‐tightly arc‐welded niobium or tantalum capsules within a few days. Exceptions are europium and ytterbium which do not react to form the corresponding fluoride sulfides under these conditions. However, at least YbFS becomes accessible through this method if platinum serves as container material. With sodium chloride (NaCl) as a flux, the formation of hydrolysis‐insensitive, platelet‐shaped A‐type single crystals with square cross‐section and the formula MFS (M = La–Nd, Sm, Gd–Er) is possible. These are very suitable for structure refinement from X‐ray diffraction data. In the PbFCl‐analogous crystal structures (tetragonal, P4/nmm, Z = 2; LaFS: a = 404.38(4), c = 700.41(7) pm; CeFS: a = 400.13(3), c = 696.20(5) pm; PrFS: a = 396.27(3), c = 692.72(5) pm; NdFS: a = 393.89(3), c = 691.58(5) pm; SmFS: a = 388.36(3), c = 687.95(5) pm; GdFS: a = 383.45(3), c = 685.18(5) pm; TbFS: a = 381.02(3), c = 683.86(5) pm; DyFS: a = 378.48(2), c = 682.51(4) pm; HoFS: a = 376.48(3), c = 681.92(5) pm; ErFS: a = 374.61(3), c = 681.34(5) pm), the M³⁺ cations are surrounded by nine anions (4 F^– and 5 S^2–) as monocapped square antiprisms. The anions themselves exhibit tetrahedral (F^–) and square‐pyramidal (S^2–) cationic coordination, respectively, according to the Niggli formula {(M³⁺)(F^–)_4/4(S^2–)_5/5}. In the case of TmFS, YbFS, and LuFS under analogous conditions, the hexagonal B‐ or trigonal C‐type modifications form at first, which can be transformed eventually to the quenchable metastable tetragonal A‐type polymorphs (TmFS: a = 372.86(5), c = 681.15(8) pm; YbFS: a = 371.08(5), c = 680.93(8) pm; LuFS: a = 369.37(5), c = 680.76(8) pm) at high pressure (20–60 kbar).     

Das erste oligomere Oxoindat(III): K14[In4O13]

The First Oligooxoindate(III): K₁₄[In₄O₁₃] For the first time K₁₄[In₄O₁₃] was obtained by heating intimate mixtures of K₂O, CdO and elementar In (molar ratio 3.1:1.0:1.0) in closed Ag-cylinders (30 days, 450°C) in form of yellow-brown single crystals. The structure determination by four circle diffractometer data MoKα, 3 689 out of 3 689 I_o(hkl), R = 4.22, R_w = 2.45) confirms the space group P2₁/c with lattice constants a = 687.7 pm; b = 3 118.5 pm; c = 686.4 pm; β = 119.3°; Z = 2. The characteristic feature of the structure is [In₄O₁₃]^14? groups, oligomers consisting of four corner-sharing InO₄ tetrahedra. These groups are connected by crystallographically distinct potassium atoms. The structure is isotypic with Na₁₄[Al₄O₁₃] [2] and K₁₄[Fe₃O₁₃] [3]. ECoN and MAPLE calculationes are discussed.     

Struktur‐ und magnetochemische Untersuchungen an KCuGaF6

Structural and Magnetochemical Studies on KCuGaF₆ The crystal structure of KCuGaF₆ was determined on the base of X‐ray single crystal data (wR₂ = 0.084 for 2476 independent reflections). The compound crystallizes with a = 728.56(4), b = 989.51(6), c = 676.27(3) pm, β = 93.120(5)°, Z = 4 in space group P2₁/c of the pyrochlore related KCuCrF₆ type. The octahedral coordinations [GaF₆] and [CuF₆] are slightly resp. strongly distorted (mean values Ga‐F: 188.2 pm resp. Cu‐F: 188.2/200.1/227.6 pm). The longest distances Ga‐F and the shortest ones Cu‐F are found within octahedral chains of these two kinds of atoms, running along [100] and [001], resp., and being mutually bridged as well (M‐F‐M in between 114 and 145°). The magnetic mole susceptibilities measured at powders and at a single crystal follow the isotropic Heisenberg model for S = ¹/₂, if effects of chain disrupture are considered in the form of some paramagnetic portion. No indication of threedimensional magnetic order is observed down to T = 2 K and low magnetic fields H < 100 G. KCuGaF₆ (J/k = —71 K for the powder) is distinguished this way from the chain structure compounds KCuAlF₆ und Na₂CuScF₇ (J/k = —76 resp. —59 K) which were also magnetically studied and yield similar antiferromagnetic exchange constants J/k.     

Pniktogenidostannate(IV) mit isolierten Tetraeder‐Anionen: Neue Vertreter (E1)4(E2)2[Sn(E15)4] (mit E1 = Na,K; E2 = Ca,Sr, Ba; E15 = P,As, Sb,Bi) vom Na6[ZnO4]‐Typ und die Überstrukturvariante von K4Sr2[SnAs4]

Pnictogenidostannates(IV) with Discrete Tetrahedral Anions: New Representatives (E1)₄(E2)₂[Sn(E15)₄] (with E1 = Na, K; E2 = Ca, Sr, Ba; E15 = P, As, Sb, Bi) of the Na₆[ZnO₄] Type and the Superstructure Variant of K₄Sr₂[SnAs₄] The silvery to dark metallic lustrous compounds (E1)₄(E2)₂[Sn(E15)₄] (E1 = Na, K; E2 = Ca, Sr, Ba; E15 = P, As, Sb, Bi) were prepared from melts of stoichiometric mixtures of the elements. They crystallize in the Na₆[ZnO₄]‐type structure (hexagonal, space group: P6₃mc, Z = 2; Na₄Ca₂[SnP₄]: a = 938.94(7), c = 710.09(8) pm; K₄Sr₂[SnAs₄]: a = 1045.0(2), c = 767.0(1) pm; K₄Ba₂[SnP₄]: a = 1029.1(6), c = 780.2(4) pm; K₄Ba₂[SnAs₄]: a = 1051.3(1), c = 795.79(7) pm; K₄Ba₂[SnSb₄]: a = 1116.9(2), c = 829.2(1) pm; K₄Ba₂[SnBi₄]: a = 1139.5(2), c = 832.0(2) pm). The anionic partial structure consists of tetrahedra [Sn(E15)₄]^8– orientated all in the same direction along [001]. In the cationic partial structure one of the two cation positions is occupied statistically by alkali and alkaline earth metal atoms. Up to now only for K₄Sr₂[SnAs₄] a second modification could be isolated, forming a superstructure type with three times the unit cell volume (hexagonal, space group: P6₃cm, Z = 6; a = 1801.3(2), c = 767.00(9) pm) and an ordered cationic partial structure.     

Alkalimetallbismutide ABi und ABi2 (A = K,Rb, Cs) — Synthesen,Kristallstrukturen, Eigenschaften

Alkali Metal Bismuthides ABi and ABi₂ — Synthesis, Crystal Structure, Properties The Zintl phases ABi (A = K/Rb/Cs; monoclinic, space group, P2₁/c, a = 1422.3(2)/1474.2(2)/1523.7(3), b = 724.8(1)/750.2(1)/773.7(1), c = 1342.0(2)/1392.1(2)/1439.9(2) pm and β = 113.030(3)/113.033(2)/112.722(3)°, Z = 16) crystallize with the β‐CsSb structure type containing chains of two‐connected Bi atoms. Hence, and according to calculated electronic structures, they are semiconductors with small band gaps of approx. 0.5 eV. In contrast, the compounds ABi₂ (A = K/Rb/Cs; cubic, space group Fd3¯m, a = 952.1(2)/962.4(8)/972.0(3) pm, Z = 8) belong to the Laves phases, showing a typical metallic electrical conductivity and no band gaps.     

Darstellung,Kristallstrukturen und Schwingungsspektren von Verbindungen mit den linearen Dipnictidoborat(3–)‐Anionen [P–B–P]3–, [As–B–As]3– und [P–B–As]3–

Synthesis, Crystal Structure, and Vibrational Spectra of Compounds with the Linear Dipnictidoborate (3–) Anions [P–B–P]^3–, [As–B–As]^3–, and [P–B–As]^3– The alkali metal boron compounds M₃[BX₂] with X = P, As are synthesized from the alkali metals M and the binary components MX or M₄X₆ and BX in sealed steel ampoules (phosphides) or niobium ampoules (arsenides) at 1000 K. The compounds are obtained as bright yellow prisms (M₃[BP₂]) or plates (K₂Na[BP₂]) and yellow‐red prismatic crystals (M₃[BAs₂], Cs₃[BPAs]) which are very sensitive against oxidation and hydrolysis. Three different structure types are formed, namely K₂Na[BP₂] (C2/m (No. 12); Z = 4; a new mC24 structure type); Na₃[BP₂] (P2₁/c (No. 14); Z = 4, β‐Li₃[BN₂] type), M₃[BX₂] with M = K, Rb, Cs and X = P, As and Cs₃[P–B–As] (C2/c, (No. 15); Z = 4, K₃[BP₂] type). The bond lengths of the linear [BX₂]^3– anions are hardly changed and correspond to a Pauling bond order PBO = 1.9 (d(B–P) = 176.7–177.1 pm; d(B–As) = 186.5–188.0 pm). The vibrational spectra confirm the existence of unmixed and mixed units [P–B–P]^3–, [As–B–As]^3– and [P–B–As]^3– with D_∞h and C_∞v symmetry, respectively. The valence force constants f(B–X) and the corresponding Siebert bond orders, calculated from the frequencies, are discussed and compared with those of the isoelectronic anions and molecules.     

Das System Gd/Co/B: Darstellung und röntgenographische Charakterisierung von GdCo4B,Gd3Co11B4, GdCoB4 und GdCo12B6

The System Gd/Co/B: Preparation and Characterization by X‐ray Diffraction of GdCo₄B, Gd₃Co₁₁B₄, GdCoB₄, and GdCo₁₂B₆ The compounds GdCo₄B, Gd₃Co₁₁B₄, GdCoB₄, and GdCo₁₂B₆ were characterized by X‐ray investigations of single crystals. GdCo₄B (P 6/mmm, a = 505.9(1) pm, c = 690.1(1) pm) crystallizes with the CeCo₄B structure type; Gd₃Co₁₁B₄ (P 6/mmm, a = 508.7(1) pm, c = 982.9(9) pm) with the Ce₃Co₁₁B₄ stucture type; GdCo₁₂B₆ ( , a = 949.5(1) pm, c = 747.4(1) pm) with the SrNi₁₂B₆ structure type and GdCoB₄ (P bam, a = 591.3(9) pm, b = 1145.1(6) pm, c = 346.2(3) pm) with the YbCoB₄ structure type.     

IV Dodekaedrische [Mo(CN)8]‐Koordination in den cyanoverbrückten Cobalt‐ und Nickel‐Amminkomplexen MII2(NH3)8[Mo(CN)8] · 1,5 H2O (MII = Co,Ni) und Ni2(NH3)9[Mo(CN)8] · 2 H2O

Crystal Structures of Octacyanomolybdates(IV). IV Dodecahedral [Mo(CN)₈] Coordination of the Cyano‐Bridged Cobalt and Nickel Ammin Complexes M^II₂(NH₃)₈[Mo(CN)₈] · 1.5 H₂O (M^II = Co, Ni) and Ni₂(NH₃)₉[Mo(CN)₈] · 2 H₂O At single crystals of the hydrated cyano complexes Co₂(NH₃)₈[Mo(CN)₈] · 1.5 H₂O (a = 910.0(4), b = 1671(2), c = 1501(1) pm, β = 93.76(6)°) and Ni₂(NH₃)₈[Mo(CN)₈] · 1.5 H₂O (a = 899.9(9), b = 1654.7(4), c = 1488(1) pm, β = 94.01°), isostructurally crystallizing in space group P2₁/c, Z = 4, and of trigonal Ni₂(NH₃)₉[Mo(CN)₈] · 2 H₂O (a = 955.1(1), c = 2326.7(7) pm, P3₁, Z = 3), X‐ray structure determinations were performed at 168 resp. 153 K. The [Mo(CN)₈]^4– groups of the three compounds, prepared at about 275 K and easily decomposing, show but slightly distorted dodecahedral coordination (mean distances Mo–C: 216.3, 215.4 and 216.1 pm). Within the monoclinic complexes the anions twodimensionally form cyano bridges to the ammin cations [M(NH₃)₄]²⁺ and are connected with the resulting [MN₆] octahedra (Co–N: 215.1 pm, Ni–N: 209.8 pm) into strongly puckered layers. The trigonal complex exhibits a chain structure, as one [Ni(NH₃)₅]²⁺ cation is only bound as terminal octahedron (Ni–N: 212.0 pm). Details and the influence of hydrogen bridges are discussed.     

Structure,Chemical Bonding and Properties of CoIn3, RhIn3, and IrIn3

CoIn₃, RhIn₃, and IrIn₃ were synthesized by reacting the elements in sealed tantalum tubes at 1170 K and subsequent annealing at 770 K. The structures of the three compounds (FeGa₃ type, space group P4₂/mnm) were refined from single crystal X-ray data: a = 682.82(6), c = 709.08(7) pm, wR2 = 0.0407, 397 F² values for CoIn₃, a = 698.28(8), c = 711.11(9) pm, wR2 = 0.0592, 418 F² values for RhIn₃, and a = 699.33(5), c = 719.08(5) pm, wR2 = 0.0625, 482 F² values for IrIn₃ with 16 parameters for each refinement. The structures may be considered as an intergrowth of tungsten-like building blocks of indium atoms and AlB₂-like slabs of compositions In&Co, In&Rh, and In&Ir, respectively. These are compared with the related intergrowth variants found for compounds with ordered U₃Si₂ and Zr₃Al₂ type structure. Semi-empirical band structure calculations for RhIn₃ reveal low density-of-states (DOS) at the Fermi level and negative Rh–Rh crystal orbital overlap populations (COOP) indicating antibonding Rh–Rh interactions. The bonding characteristics of CoIn₃, RuIn₃, and IrIn₃ are similar to RhIn₃. Magnetic susceptibility measurements of compact polycrystalline samples of CoIn₃, RhIn₃, and IrIn₃ indicate weak Pauli paramagnetism.     

Die Undecaarsenide A3As11 (A = Rb,Cs) — Synthesen und Kristallstrukturen

Alkaline Metal Arsenides A₃As₁₁ (A = Rb, Cs): Preparation and Crystal Structures Rb₃As₁₁ and Cs₃As₁₁ were synthesized from the elements and the crystal structures of the ordered room temperature form were characterized via single crystal x‐ray studies. In the Zintl phases the As atoms form chiral ufosan‐anions As with As‐As distances ranging from 238 to 248 pm. Like K₃As₁₁ Rb₃As₁₁ crystallizes with the Na₃P₁₁ structure type (orthorhombic, space group Pbcn, a = 1108.2(2), b = 1533.5(3), c = 1060.1(2) pm, Z = 4), whereas the Cs compound (monoclinic, space group C2/c, a = 1324.5(7), b = 1524.5(9), c = 1937.2(11) pm, β = 95.29(1)°, Z = 8) forms a new structure type. The crystallographic relationship between the two structure types and the anion packings in the plastic crystalline high temperature forms are discussed.     

Die Kristallstruktur von Kaliummonomethylcarbonat

Crystal Structure of Potassium Monomethylcarbonate Potassium monomethylcarbonate KCH₃CO₃ was obtained from reaction of dimethylcarbonate with potassium hydroxide in methanole. The crystal structure was determined (triclinic, P1 (no. 2), Z = 2, a = 380.9(2) pm, b = 558.9(3) pm, c = 985.3(3) pm, α = 100.71(2)°, β = 90.06(3)°, γ = 92.48(3)°, V = 205.9(2) · 10⁶ pm³, wR(F²) = 0.054, wR_obs(F) = 0.022). Structural relations between potassium monomethylcarbonate and potassium hydrogencarbonate are discussed.