Crystal structure of tetrabutylammonium nitroprusside dihydrate, [(C4H9)4N]2[Fe(CN)5NO]·2H2O, and vibrational spectra of ground and metastable excited states of the dihydrate and the anhydrate (original) (raw)
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Polyhedron, 2002
18 / Abstract / 19 / / 20 / The crystal structure of nitropentaamminecobalt(III) nitroprusside sesquihydrate, [Co(NH 3 ) 5 NO 2 ][Fe(CN) 5 NO] ×/1.5H 2 O has / 21 / been determined by Patterson and Fourier methods employing 3881 independent X-ray reflections with I /2s (I ) and refined by / 22 / full-matrix least-squares to R 1 0/0.032. The substance crystallizes in the monoclinic C 2/c (C 2h 6 ) space group No. 15, with a 0/ / 23 / 28.408(3), b 0/6.422(1), c 0/22.401(3) Å , b 0/123.55(1)8 and Z0/8. The metastable state I (MSI) of the nitroprusside anion and the / 24 / photochemical isomerization reaction of the nitropentaamminecobalt(III) cation to the nitrito isomer were produced by irradiation / 25 / with Ar ' laser light of 488 nm wavelength at 77 K. TGA and DTA of the non-excited substance were performed under nitrogen / 26 / atmosphere. # 2002 Published by Elsevier Science Ltd. / 27 / Keywords: PPPPentacyanonitrosylferrate(2(/) ion; Metastable excited states; X-ray diffraction; FIRRS; TGA; DTA / 28 / 1. Introduction / 29 / An extensive work on nitroprussides, which includes / 30 / alkaline, alkaline-earth, and transition metals salts has / 31 / been previously performed ([1 Á/10] and references / 32 / therein). These studies provided interesting results, / 33 / especially about the vibrational and photophysical NO / 34 / behavior. The strongly polar NO stretching vibration / 35 / proved to be largely affected by the environment, as / 36 / suggested by resonant (interanionic) ([10] and references / 37 / therein) and non-resonant (lattice) effects experienced / 38 / by this stretching mode in salts containing the / 39 / [Fe(CN) 5 NO] 2( (NP) anion. [9,11] The MNO group, / 40 / in this and other pentaligandnitrosyl anions, [12 Á/17] / 41 / seems to be the site of the generation of two very long-/ 42 / lived metastable states (MSI and MSII) by irradiation at / 43 / low temperature with light in the 300 Á/550 nm wave-/ 44 / length range. A geometrical interpretation has been / 45 / proposed for MSI and MSII with a nearly linear / 46 / structure (FeON) for MSI and T-shaped Fe N O for MSII / 47 / [18] as results of very refined single crystal X-ray / 48 / diffraction studies. Recently, additional information / 49 / was obtained in favor of the linear, isonitrosyl structure / 50 / of MSI from the IR studies of 15 NO, N 18 O and 54 Fe-/ 51 / substituted excited sodium nitroprusside dihydrate / 52 / (SNP) and a DFT vibrational calculation [19].
J Chem Crystallography, 1999
The crystal structure of rubidium nitroprusside monohydrate, Rb 2 [Fe(CN) 5 NO] и H 2 O, has been determined from X-ray diffraction data and refined using direct and Fourier methods to R ϭ 0.066 and Rw ϭ 0.075, employing 1894 independent reflections with I Ͼ 3 (I). The substance crystallizes in the monoclinic space group C2/c (C 6 2h), with a ϭ 13.987(2), b ϭ 10.241(1), c ϭ 18.151(1) Å , ͱ ϭ 110.94Њ, and Z ϭ 8. Anions are located at C 1 sites, one per asymmetric unit, and are slightly distorted octahedra. TGA, DTA, FTIR, and FTIR Raman results were interpreted on the basis of the formula of the compound, its crystal structure, and the behavior of other nitroprussides.
Structure of calcium nitroprusside tetrahydrate
Acta Crystallographica Section B Structural Crystallography and Crystal Chemistry, 1980
mm-1 (Mo Ka), F(000) = 324. The structure was solved by the heavy-atom method. A full-matrix least-squares refinement proceeded to R = 0.041 for 1966 unique reflections (Rsy m "-0.021) measured by counter methods. An antiparallel alignment of the NC dipoles along b was observed as well as seven-coordinated Ca 2÷ ions. Introduction. The determination of the structure of the title compound was undertaken as part of a series of chemical, spectroscopic, TGA-DTA and structural studies of alkaline-earth nitroprussides (Lanfranconi,
Infrared and Raman spectra of -thallium nitroprusside, Tl2[Fe(CN)5NO]
Vibrational Spectroscopy, 2000
Ž w Ž. x. Interferometric infrared and Raman spectra of thallium nitroprusside Tl Fe CN NO , with normal isotopic composi-2 5 13 Ž. y1 Ž. tion or substituted with C 98.5% , were obtained from 4000 to 50 cm at room and low temperature boiling liquid air. Infrared microscopy used with selected monocrystals allowed the detection of very weak overtone and combination bands. Comparisons are made with other nitroprusside salts, anhydrous and hydrated, and especially with sodium nitroprusside dihydrate.
Journal of Chemical Crystallography, 1996
The title compound, Rb2[Fe(CN)sNO], crystallizes in the space group P212~2~, with a = 5.687(1), b = 15.956(2), c = 12.645(3) ~,, and Z = 4. Afiions are in equivalent Ci sites (one per asymmetric unit) and are slightly distorted octahedra (C4v ideal symmetry). TGA and DTA curves and vibrational (infrared and Raman) spectra of Rb2[Fe(CN)sNO] were obtained. Results are interpreted in view of the crystal structure of the compound and the behavior of related substances.
The structure of two orthorhombic nitroprussides: Cd[Fe(CN)5NO]·2H2O and Zn[Fe(CN)5NO]·2H2O
Polyhedron, 2001
When zinc and cadmium nitroprussides, obtained as powders or single-crystals samples, are aged in air they lose crystallization water and change their crystalline structure. In the stable form these two complexes are orthorhombic dihydrates with four molecules in the unit cell. In the aging process the crystals become brittle producing a polycrystalline material. The crystalline structure of these two complexes (orthorhombic dihydrates) was refined from their XRD powder patterns using the Rietveld method. As the starting model in the refining process the reported orthorhombic structure of copper nitroprusside (dihydrate) was used. The main changes in the dehydration process associated with the structural transformation take place in the coordination sphere of the outer cation (Cd or Zn).
Synthetic Metals, 2002
A single crystal X-ray diffraction (XRD) study of the radical cation salt (EDT-TTF) 3 [Fe(CN) 5 NO] has been carried out (a ¼ 6:623ð3Þ, b ¼ 10:487ð2Þ, c ¼ 15:951ð1Þ Å , a ¼ 109:19ð1Þ, b ¼ 96:30ð2Þ, g ¼ 99:15ð3Þ8, V ¼ 1017:3ð5Þ Å 3 , space group P1, Z ¼ 1). The crystals have a layered structure with the distinctive feature of the presence of alternating EDT-TTF dimers and monomers in the radical cation stacks. Both the structural features and the calculated HOMO Á Á Á HOMO interaction energies suggest that the strong intradimer interaction is responsible for the charge separation and the semiconducting properties of the salt.
Journal of Solid State Chemistry, 2003
A tetrasodium dimagnesium dihydrogen diphosphate octahydrate Na 4 Mg 2 (H 2 P 2 O 7 ) 4 Á 8H 2 O was synthesized. It crystallizes in the monoclinic system, space group P2 1 /m (no. 11), Z ¼ 4; and its unit-cell parameters are: a ¼ 8:0445ð3Þ Å , b ¼ 11:5244ð5Þ Å , c ¼ 9:0825ð4Þ Å , b ¼ 113:1401ð2Þ1; V ¼ 774:28ð6Þ Å 3 . The structure was determined by single-crystal X-ray diffractometry and refined to a R index of 0.0294 (wR ¼ 0:0727) for 1878 independent reflections with I42sðIÞ: The framework is made by the alternance of layers of MgO 6 /NaO 6 octahedra and double tetrahedra PO 4 along b-axis. Such layers are characterized by the presence of strong hydrogen bonds. (H 2 P 2 O 7 ) 2À anions exhibit bent eclipsed conformation. Besides, the crystal was analyzed by FT-IR and micro-Raman vibrational spectroscopy. No coincidences of the majority of the Raman and infrared spectra bands of Na 4 Mg 2 (H 2 P 2 O 7 ) 4 Á 8H 2 O confirms a centrosymmetric structure of this material. The vibrational spectra confirm the bent POP configuration in this compound. r