Volume 80, Issue 1-2

A new, convenient and efficient method for the construction of a new polycyclic condensed system containing an azepine and pyrazolophthalazine has been developed in the form of a two-step protocol comprising the condensation reaction of hydroxylamine with 1 H -indazolo[1,2- b ]phthalazine-1,6,11-trione derivative, followed by a Beckman rearrangement reaction using polyphosphoric acid (PPA) as catalyst. Various substituted substrates were successfully used, affording the azepino phthalazine hybrids in good yields and in short reaction times.

Gas chromatography can be based on very different types of stationary phase materials such as porous crystalline, polymeric or even liquid materials. These materials are not supposed to change significantly when brought into contact with the analytes to be investigated. Analytes may overload the stationary phase which changes the interaction between analyte and stationary phase causing often tailing or fronting in the detected peaks. In contrast to these unintended effects, new materials such as flexible porous crystalline coordination polymers can be utilized as stationary phase allowing the crystal structure to undergo transformation induced by the analytes. Depending on the analyte concentration, even a complete collaps of the porous structure can be achieved. The generic theoretical investigation presented will address the possible effects caused by state-dependent transformations of stationary phases. A first experimental realization of such a system with a well-known metal-organic framework (MOF) demonstrating unconventional chromatographic behavior was also generated and investigated.

A novel Sm(III) orotate complex, [NaSm(orotate) 4 (H 2 O) 10 ]·3H 2 O, has been synthesized and its structure determined by single crystal X-ray diffraction and vibrational (IR and Raman) spectroscopic methods. The title compound crystallizes in the non-centrosymmetric orthorhombic space group Cmc 2 1 with Z  = 4. In the crystal structure, one of the two independent orotate ligands links the Sm(III) and Na(I) cations, forming chains. The second orotate ligand completes the coordination environment of the Na(I) ion, resulting in layers that are parallel to the ab plane. This arrangement leads to an extensive three-dimensional network structure, characterized by numerous intermolecular O–H⋯O and N–H⋯O interactions.

The new double salt with the empirical formula (NH 4 ) 4 [SO 4 ][CB 11 H 12 ] 2 can be obtained by the reaction between an aqueous solution of the free acid of the closo -carbaborate (H 3 O)[CB 11 H 12 ] and aqueous ammonia (NH 3 ), when the incorporated sulfate anions are introduced by a cation exchanger due to its regeneration with sulfuric acid (H 2 SO 4 ). (NH 4 ) 4 [SO 4 ][CB 11 H 12 ] 2 is yielded as colorless, prismatically shaped crystals with a considerable size up to 1 mm. This ammonium sulfate carbaborate crystallizes in the monoclinic space group C 2/ c with the lattice parameters a  = 2715.32(9), b  = 713.91(2), c  = 1391.24(5) pm and β  = 109.203(2)° with four formula units per unit cell. Due to the formation of bridging hydrogen bonds, the [SO 4 ] 2− anions and the (NH 4 ) + cations form ∞ 2 $\overset{2}{\infty }$ {([(N1)H 4 ] 2/2 [(N2)H 4 ] 2/2 [(N3)H 4 ] 2/1 [SO 4 ]) 2+ } layers parallel to the bc plane. Between these positively charged layers, the [CB 11 H 12 ] − anions are placed in fashion of the anti -K 2 NiF 4 -type structure, where K + is replaced with [CB 11 H 12 ] − and [SO 4 ] 2− -centered [(NH 4 ) + ] 6 octahedra, which share four coplanar corners, arrange to the above-mentioned layers. In the Raman spectra of (NH 4 ) 4 [SO 4 ][CB 11 H 12 ] 2 , the dominating bands correspond to the well-known vibration modes of the closo -carbaborate cage. The bands resulting from the (NH 4 ) + and [SO 4 ] 2− ions are visible, but significantly less intense as compared to the vibrations of [CB 11 H 12 ] − , which can be explained by the formation of hydrogen bonds.

By dissolving triethylammonium dodecahydro-carba -closo -dodecaborate, mercury(II) acetate and potassium cyanide in an equimolar ratio in acetonitrile and subsequent isothermal evaporation of this solution, the new pseudo -double salt K[Hg(CN) 2 ][H 3 CCOO] could be obtained. K[Hg(CN) 2 ][H 3 CCOO] crystallizes monoclinically in the space group P 2 1 / c with the lattice parameters a  = 954.25(6), b  = 905.46(5), c  = 904.12(5) pm and β  = 90.697(3)° for Z  = 4. The Hg 2+ cations and the (CN) − anions are arranged in the crystal structure as quasi -linear molecular N≡C–Hg–C≡N units. The C≡N distances of the cyanide ligands are shorter as compared to the C≡N contacts in the pseudo -binary compound Hg(CN) 2 . These molecules reside between layers of K + cations and [H 3 CCOO] − anions, in each of which every acetate group bridges three potassium atoms. This is achieved by both the bidentate coordination of each [H 3 CCOO] − anion to one K + cation and the monodentate coordination to two further potassium ions. The coordination environment of K + is complemented by one K–N contact to an end-on coordinated cyanide anion. In the second coordination sphere, there are additionally two side-on coordinated (C≡N) − units. The Raman spectrum of K[Hg(CN) 2 ][H 3 CCOO] shows the three expected, well-known vibrations of the N≡C–Hg–C≡N molecule. These are the valence vibrations of the C≡N and the Hg–C bonds at 2171 and 383 cm −1 and the Hg–C≡N deformation vibration at 261 cm −1 . From the valence vibrations of the [H 3 CCOO] − anion, the ν (C–H) vibration can be found at 2937 cm −1 . In the range between 1300 and 1500 cm −1 both C–O/C=O valence vibrations and the H–C–H deformation vibration are visible. The intensity maximum at 904 cm −1 can be assigned to the C–C valence vibration of the acetate anion.

A (pyrrolidinyldimethylsilyl)tetramethyl zincocene was obtained by salt elimination reaction of the corresponding sodium cyclopentadienide with zinc(II) chloride and was characterized in solution and in the solid state, including the determination of its crystal structure. Furthermore, the zinc center was shown to exhibit Lewis-acidic character by coordination of an N-heterocyclic carbene.

SrPd 2 Sn 2 was synthesized by a reaction of the elements in a sealed tantalum tube in an induction furnace followed by annealing in a muffle furnace to increase crystallinity. The polycrystalline sample was studied by powder X-ray diffraction: P 4/ nmm , a = 464.00(7), c = 1,058.4(4) pm and V = 0.2279 nm 3 . The CaBe 2 Ge 2 -type structure was refined from single-crystal X-ray diffractometer data: a = 464.09(4), c = 1,059.64(8) pm, w R = 0.0507, 307 F 2 values and 17 variables. The single crystal shows small defects (95.9(5) %) on the Pd2 site and 73(5) % Sn2/27 % Pd3 mixing on one 2 c site. The refined composition of the single crystal is SrPd 2.23 Sn 1.73 . The palladium and tin atoms form a three-dimensional, covalently bonded [Pd 2.23 Sn 1.73 ] network with short Pd–Sn distances (263.3–271.4 pm). The two crystallographically independent palladium atoms in the network have tetrahedral and square pyramidal tin coordination, respectively. Within the [Pd 2.23 Sn 1.73 ] network the strontium atoms fill larger cavities. The strontium atoms are coordinated by nine palladium and nine tin atoms.

The crystal structure of sodium tricyanomethanide Na[C(CN) 3 ] has been confirmed by Rietveld refinement of X-ray powder diffraction data. Additionally, Raman and IR spectra of the title compound have been recorded exhibiting spectra in good agreement with those of other tricyanomethanides. Despite Na[C(CN) 3 ] and K[C(CN) 3 ] crystallizing both in the triclinic space group P 1 ‾ $\overline{1}$ (no. 2), with seemingly similar unit cell parameters, it is demonstrated that they are clearly not isotypic compounds.