The crystal structure of Fe(SeO2OH)(SeO4)·H2O

Summary The crystal structure of the hydrothermally synthesized compound Fe(SeO₂OH) (SeO₄) · H₂O was determined by single crystal diffraction methods:a=8.355(2) Å,b=8.696(2) Å,c=9.255(2) Å, =93.72(1)°,V=670.95 ų;Z=4, space group P2₁/c,R=0.029,R _w=0.027 for 2430 independent reflections (sin /0.76 Å^–1). Isolated FeO₅(H₂O)-octahedra share five corners with [SeO₂OH] and [SeO₄] groups to form sheets parallel to (100). These sheets are interconnected via hydrogen bonds only.

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Die Kristallstruktur von Fe(SeO₂OH)(SeO₄)·H₂O

Zusammenfassung Die Kristallstruktur der hydrothermal dargestellten Verbindung Fe(SeO₂OH) (SeO₄)·H₂O wurde mittels Einkristallbeugungsmethoden bestimmt:a=8.355(2) Å,b=8.696(2) Å,c=9.255(2) Å, =93.72(1)°,V=670.95 ų;Z=4, Raumgruppe P2₁/c,R=0.029,R _w=0.027 für 2 430 unabhängige Reflexe (sin / 0.76 Å^–1). Isolierte FeO₅(H₂O)-Oktaeder teilen fünf Ecken mit [SeO₂OH]- und [SeO₄]-Gruppen, wobei sie Schichten parallel (100) bilden. Diese Schichten sind nur über Wasserstoffbrücken miteinander verbunden.

     

Crystal structures and vibrational spectra ofMSnF6·6H2O(M=Fe,Co, Ni)

Summary Single crystal X-ray structural data (atT=300 K) are reported for CoSnF₆·6H₂O (rhombohedral; R{ie61-1}-C _3i ² ;a=9.735(7) Å,c=10.095(7) Å, =120°;Z=3;R=0.047) and for NiSnF₆· 6H₂O (rhombohedral; R{ie61-2}-C _3i ² ;a=9.697(1)Å,c=10.021(1)Å, =120°;Z=3;R=0.038). The two compounds are isostructural to FeSnF₆·6H₂O. IR and Raman spectroscopic data (atT=300 and 75 K) are reported for hydrated and for partially deuterated samples ofMSnF₆·6H₂O (M=Fe, Co, Ni). Two rather similar (OD) stretching frequencies and one (HDO) bending frequency of isotopically dilute HDO molecules are observed for either of the three compounds, which is consistent with one crystallographically distinct water molecule forming two different, but rather similar O ... F hydrogen bonds.

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Kristallstrukturen und Schwingungsspektren vonMSnF₆·6H₂O (M=Fe, Co, Ni)

Zusammenfassung Die Kristallstrukturen von CoSnF₆·6H₂O (rhomboedrisch; R{ie61-3}-C _3i ² ;a=9.735(7) Å,c=10.095(7) Å, =120°;Z=3;R=0.047) und von NiSnF₆·6H₂O (rhomboedrisch; R{ie61-4}-C _3i ² ;a=9.697(1)Å,c=10.021(1)Å, =120°;Z=3;R=0.038) wurden mittels Röntgen-Einkristalldaten (beiT=300 K) bestimmt. Die beiden Verbindungen sind isostrukturell zu FeSnF₆·6H₂O. IR- und Raman-Spektren vonMSnF₆·6H₂O (M=Fe, Co, Ni) wurden von Proben mit unterschiedlichem Deuterierungsgrad gemessen (beiT=300 und 75 K). Bei allen drei Verbindungen findet man für isotopenverdünnte HDO Moleküle zwei nur geringfügig unterschiedliche (OD)-Valenzfrequenzen und eine (HDO)-Deformationsfrequenz, was mit der Existenz von nur einer Art von Wassermolekülen mit zwei verschiedenen, aber doch sehr ähnlichen O ... F Wasserstoffbrückenbindungen übereinstimmt.

     

Structure of the neutral metal complex Pt(dddt)2

A neutral metal complex, [Pt(dddt)₂]° (1), has been obtained by oxidation of the [Pt(dddt)₂]^– anion with excess (Bu₄N)AuBr₄ in nitrobenzene. Crystallographic data for 1a=17.854(9) Å,b=18.409(9) Å,c=4.717(5) Å, =68.83(2)°, space group P2₁/n,Z=4,d _calc=2.55 g/cm³. In1 two independent centrosymmetric [Pt(dddt)₂]° molecules are packed in stacks that form layers parallel to the (110) plane. The molecules of1 in the layers have shortened S...S contacts 3.491(9) Å, and 3.594(10) Å. The average bond lengths Pt-S 2.242(7) Å, S-C 1.71(2) Å and C=C 1.40(3) Å, together with the square-planar coordination of Pt in PtS₄, suggest considerable conjugation in the metal cycles.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1207–1209, July, 1993.     

The polyiodide salts: Pyridinium pentaiodide;β-naphthylammonium pentaiodide; andN-methyl-γ-picolinium heptaiodide. Structures with channel inclusion features

The crystal structures of three polyiodode salts are reported (pyridinium pentaiodide, monoclinic,P2 ₁/m,a=9.221(5),b=12.918(5),c=6.026(4) Å, =103.60(7)^o,Z=2,R _F=0.087 for 1187 intensities; -naphthyl-ammonium pentaiodide, triclinic,173-1,a=10.390(5),b=9.502(5),c=4.462(3) Å, =99.19(7), =90.40(7),=108.49(8)^o,Z=2,R _F=0.059 for 1319 intensities;N-methyl--picolinium heptaiodide, monoclinic,C2/c,a=19.315(7),b=12.714(5),c=8.442(4) Å, =107.26(7)^o,Z=4,R _F=0.065 for 1336 intensities). All three structures can be described as having channel inclusion features; the cations are contained in channels in polyiodide frameworks based on different arrangements of I₂ molecules and I ₃ ^– anions. This structural type is the converse of the more widespread kind where polyiodide anions are contained in an organic matrix (e.g., cyclodextrin polyiodides). Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82016 (30 pages).Part X of Crystal Structures of Polyiodide Salts and Complexes. For Part IX, see F. H. Herbstein, G. M. Reisner, and W. Schwotzer,Acta Crystallogr. C, accepted for publication, 1984     

Synthesis and Structure of Complexes Formed in the CuCl2–Cu–N-allylquinolinium Chloride System

The crystals of [C₉H₇N(C₃H₅)]₂Cu^IICl₄(IV) were obtained through ac electrochemical synthesis using CuCl₂· 2H₂O, N-allylquinolinium chloride, and copper electrodes in an ethanol-benzene medium. These crystals transformed with time into crystals of the [C₉H₇N(C₃H₅)][Cu^IICl₃(C₉H₇N)] complex (V). When tin(II) chloride was added to the initial reagents, the [C₉H₇N(C₃H₅)]Cu^I ₂Cl₃complex (VI) was obtained. The X-ray diffraction analysis (DARCh-1 autodiffractometer, MoK radiation, Zr filter) indicated that complexes IVand Vcrystallize in the triclinic system: space group P ; for IV, a= 12.817(4), b= 10.435(3), c= 9.606(3) Å, = 97.94(2)°, = 107.28(2)°, = 95.99(2)°, V= 1200.6(6) ų, Z= 2; for V, a= 16.992(5), b= 8.243(2), c= 7.345(3) Å, = 91.89(3)°, = 91.19(3)°, = 88.18(3)°, V= 1027.5(6) ų, Z= 2. Crystals VIare monoclinic, space group P2₁/n, a= 13.578(5), b= 15.079(4), c= 6.953(4) Å, = 105.08(4)°, V= 1370.6(10) ų, Z= 4. Structures IV–VIconsist of N-allylquinolinium cations and different anions: isolated [CuCl₄]^2–tetrahedrons (IV), [C₉H₇NCuCl₃]^–tetrahedrons (V) containing a quinoline molecule, and a polymer chain |[Cu^I ₄Cl₆]^2–} _n (VI) in which two independent metal atoms have trigonal-pyramidal and planar-trigonal environments. The C=C bond of the allyl group is not involved in cooordination with the Cu(I) atom.     

Preparation and x-ray structure determination of penta-and tetracyano-oxomolybdenum(IV) anions. The influence of water on their reactivity

Summary Several penta-and tetracyanooxomolybdenum(IV) anions have been synthesized containing different numbers of H₂O molecules, either coordinated or present as crystallisation molecules. The influence of these molecules on the reactivity of the complex, especially towards O₂, is discussed. Three compounds were characterized by x-ray structure determination. [Mo(O)(CN)₅(H₂O)₂(MeCN)₂][PPh₄]₄Cl belongs to triclinic space group P-1 witha=13.146(3) Å,b=16.944(5) Å,c=21.761(6) Å, =84.72(2)°, =87.15(2)° and =85.25(2)°. The volume of the unit cell is 4678(6)ų withz=2. The structure was refined to R=6.5%. [Mo(O)(CN)₄(H₂O)·6H₂O][PPh₄]₂ belongs to monoclinic space group P2₁/n witha=15.313(2)Å,b=19.983(3)Å,c=17.006(2)Å, =100.51(2)°. The volume of the unit cell is 5117(3)ų withz=4. The structure was refined to R=8.7%. [Mo(O)(CN)₄(MeCN)](PH₃)₂N]₂ belongs to triclinic space group P-1 witha=13.770(4)Å,b=16.292(5)Å,c=16.889(5)Å, =73.23(2)°, =72.02(2)° and =71.57(2)°. The volume of the unit cell is 3342(3)ų withz=2. The structure was refined to R=7.2%.     

Crystal structures of Co3(SeO3)3·H2O and Ni3(SeO3)3·H2O,two new isotypic compounds

Summary The crystal structures of the new, hydrothermally synthesized, isotypic compounds Co₃(SeO₃)₃·H₂O and Ni₃(SeO₃)₃·H₂O were determined by direct and Fourier methods and refined toR _w=0.023, 0.032 using single crystal X-ray data up to sin/=0.81 Å^–1 [space group P ,a=8.102 (2), 7.986 (3) Å;b=8.219 (2), 8.133 (3) Å;c=8.572 (2), 8.422 (3) Å, =69.15 (1), 69.50 (1)°; =62.88 (1), 62.50 (1)°; =67.23 (1), 67.64 (1)°;Z=2]. The structures are built up from [Me ₅(SeO₃)₆·2H₂O]^2– sheets containing three crystallographically different types of octahedrally coordinatedMe ²⁺ and trigonal pyramidal coordinated Se⁴⁺ atoms, respectively. These sheets are linked only by a fourth type ofMe ^2+[6] atom. All coordination polyhedra deviate significantly from their ideal shapes, bond lengths within the extremly distortedMe(4)O₆ polyhedra range from 1.983 (2) Å to 2.403 (2) Å in Co₃(SeO₃)₃·H₂O and from 1.987 (4) Å to 2.301 (3) Å in the Ni compound, O-Se-O bond angles were found between 92.8 (2)° and 104.9 (1)°. Hydrogen bond lengths are 2.802 (3)Å and 2.600 (4)Å in the Co compound, and 2.762 (6) Å and 2.561 (6) Å in Ni₃(SeO₃)₃·H₂O. The latter is one of the shortest known hydrogen bonds donated by a water molecule.

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Die Kristallstrukturen von Co₃(SeO₃)₃·H₂O und Ni₃(SeO₃)₃·H₂O, zwei neue isotype Verbindungen

Zusammenfassung Die Kristallstrukturen der neuen, hydrothermal synthetisierten, isotypen Verbindungen Co₃(SeO₃)₃·H₂O und Ni₃(SeO₃)₃·H₂O wurden mit direkten und Fourier-Methoden bestimmt und unter Verwendung von Einkristallröntgendaten bis sin/=0.81 Å^–1 aufR _w-Werte von 0.023, 0.032 verfeinert [Raumgruppe P ,a=8.102 (2), 7.986 (3) Å;b=8.219 (2), 8.133 (3) Å;c=8.572 (2), 8.422 (3) Å, =69.15 (1), 69.50 (1)°; =62.88 (1), 62.50 (1)°; =67.23 (1), 67.64 (1)°;Z=2]. Die Strukturen werden von [Me ₅(SeO₃)₆·2H₂O]^2– Schichten aufgebaut, die je drei kristallographisch unterschiedliche Arten von oktaedrisch koordiniertenMe ²⁺ und trigonal pyramidal koordinierten Se⁴⁺ Atomen enthalten. Diese Schichten sind nur durch eine vierte Art vonMe ^2+[6] Atomen verknüpft. Alle Koordinationspolyeder weichen deutlich von ihren Idealformen ab, Bindungslängen in den extrem verzerrtenMe(4)O₆ Polyedern variieren zwischen 1.983 (2) Å und 2.403 (2) Å in Co₃(SeO₃)₃·H₂O und zwischen 1.987 (4) Å und 2.301 (3) Å in der Ni-Verbindung, O-Se-O-Bindungswinkel liegen zwischen 92.8 (2)° und 104.9 (1)°. Wasserstoffbrückenlängen sind 2.802 (3) Å und 2.600 (4) Å in der Co-Verbindung, und 2.762 (6) Å und 2.561 (6) Å in Ni₃(SeO₃)₃·H₂O. Letztere ist eine der kürzesten bekannten Wasserstoffbrücken eines Wassermoleküls.

     

Neutral molecule/crown ether interactions 5. Comparison of the C−H acidic interactions of nitromethane and acetonitrile with 18-crown-6 and dibenzo-18-crown-6. Crystal structures of dibenzo-18-crown-6·2 CH3NO2 and dibenzo-18-crown-6·2 CH3CN

Complete structural characterization of dibenzo-18-crown-6·2 CH₃NO₂ and dibenzo-18-crown-6·2 CH₃CN have been carried out, including location and refinement of the methyl hydrogen atoms. Dibenzo-18-crown-6·2 CH₃NO₂ is monoclinic,P2₁/c, with (at –150°C)a=9.573(2),b=14.636(2),c=33.471(7) Å, =93.77(2)°, andD _calc=1.37 g cm^–3 forZ=8. Interactions between the solvent methyl groups and the crown ethers and other solvent nitro groups associate the 1 : 2 complexes into polymeric chains alongb. The acetonitrile adduct exists as discreet 1 : 2 complexes in the solid state with C–H...O interactions exlusively to the ether. This complex is triclinic,P 1, with (at –150°C)a=9.458(6),b=9.570(5),c=14.404(5) Å, =73.18(4), =79.85(5), =66.82(6)°, andD _calc=1.28 g cm^–3 forZ=2. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82070 (22 pages).For part 4, see reference [1].     

Hydrogen bonding in 2-hydroxybenzoic, 2-hydroxythiobenzoic,and 2-hydroxydithiobenzoic acid. A structural and spectroscopic study

Summary X-ray structural data are reported for 2-hydroxythiobenzoic acid (T=200 K;P2₁/a;a=14.903(5) Å,b=5.203(3) Å,c=9.114(6) Å, =92.40(4)°;Z=4;R=0.049) and 2-hydroxydithiobenzoic acid (T=297 K;P2₁/a;a=14.416(3) Å,b=13.447(3) Å,c=3.947(1) Å, =90.96(2)°;Z=4;R=0.047). In 2-hydroxythiobenzoic acid, each two molecules form cyclic dimersvia S-H...O=C hydrogen bonds, analogous to the association pattern of 2-hydroxybenzoic acid. In 2-hydroxydithiobenzoic acid, the molecules are linked to chains by S-H...O(H)-C hydrogen bonds. Solid state IR, and solution IR and NMR spectroscopic data of 2-hydroxybenzoic acid, 2-hydroxythiobenzoic acid, and 2-hydroxydithiobenzoic acid are summarized. The main characteristics of the intramolecularly associated phenolic O-H groups of the three title compounds are for the solids, for solutions (CCl₄), and _OH=10.21, 10.53, 12.20 ppm for solutions (CCl₄:CDCl₃=5:1).Dedicated to Prof.O. Olaj on the occasion of his 60^th birthday     

The x-ray crystal structure,resolution and absolute configuration of thecis-α-dichloro(1, 8-diamino-3, 6-diazaoctane)-ruthenium(III) cation

Summary Acis- configuration for the [RuCl₂(trien)]Cl·2H₂O (trien=1, 8-diamino-3, 6-diazaoctane) complex has been confirmed by an x-ray crystal structure determination. Crystals are monoclinic, space group P2₁/c witha=7.336 (1),b=8.477 (2),c=23.181 (4) Å, =103.3 (1)°, U=1403 (1) Å.³ Z=4 and M=389.7, D_c=1.84 g cm^–3. The structure was refined by full matrix least squares methods to final residual values of R=0.025 and R_w=0.033 on the basis of 3882 unique reflections. The complex has been resolved into its optical isomers using the (+)1, 2-diaminoethanebis(oxalato)cobaltate(III) anion and the absolute configuration assigned.     

Synthesis,spectroscopic and structural studies of tris(3-methyl-pyridinium)(3-ethylpyridinium)β-octamolybdate monohydrate

Summary Three isostructural compounds of general formula (3-MepyH) _x (3-EtpyH)_4–x [Mo₈O₂₆] (x=0, 2, 4) crystallize in the monoclinic system, space group P2₁/n, Z=2. Previously determined parameters for the compoundx=4 area=13.652(2),b=10.887(1),c=13.759(1) Å, =90.87(1)°,V=2044.8(4) ų,Dx=2.53,Do=2.54(1) mg m^–3,F(000)=1496. Slight differences in cell dimensions have been observed whenx=0 or 2. A nonisomorphous compound of formula (3-MepyH)₃(3-EtpyH)[Mo₈O₂₆]·H₂O crystallizes in the triclinic system, space group P2₁/n,Z=2,a=10.918(1),b=10.985(3),c=18.991(2) Å, =97.19(2), =91.45(2), =107.30(2)⁰,V=2152.8(7) ų,Dx=2.456,Do=2.456(5) mg m^–3,F(000)=1532. The distinguishing features of tris(3-methylpyridinium)(3-ethylpyridinium) -octamolybdate monohydrate are its non-centrosymmetric polyanion and its extensive hydrogen bonding. The asymmetric unit contains three independent 3-methylpyridinium and one 3-ethylpyridinium cations, one water molecule and the -octamolybdate anion. The planar cations are oriented to permit hydrogen bonds with either molybdate oxygen atoms or water oxygen atoms. Four different types of hydrogen bonds have been found: N–H...O (mono- and bifurcated); N–H...Ow (monofurcated); Ow–Hw...O (monofurcated); and C–H...O (monofurcated). The proposed hydrogen bonding interactions appear to stabilize the structure.     

The W2Cl4(NHCMe3)2(PR 3)2 molecules (R 3=Me3, Et3, Pr n 3, Me2Ph) I. Their isomeric forms,interconversion proeesses,crystalline forms,and detailed molecular structures

A thorough study of compounds with the formula W₂Cl₄(NHCMe₃)2(PR₃)₂, withR ₃=Me₃, Et₃, Prg ⁿ ₃ Me₂,Ph, is reported. In addition to the previously reported crystalline compounds, namely Ia,trans-W₂Cl₄(NHCMe₃)₂(PMe₃)₂ in space group Pmmn;3a,trans-W₂Cl₄(NHCM₃)₂(PEt₃)₂ in space group P2₁/^a (or P2₁/^c); and4,cis-W₂Cl₄(NHCMe₃)₂(PMe₂Ph)₂ in Pna2₁, we have obtained and structurally characterized the following new substances,1b,trans-W₂Cl₄,(NHCMe₃)₂(PMe₂)₂, space group P2₁/^c,a= 12.233 (4) Å,b= 12.872 (4) Å,c=17.095 (5) Å,=93.52 (2)°,Z=4,V=2687 (1) ų 2,cis-W₂Cl₄(NHCMe₃)₂(PMe₃)₂, P2₁/^c,a=9.673 (4) Å,b=17.249 (4) Å,c=16.244 (5) Å,=99.63 (3),Z = 4 ,V=2669 (1) Å.3b,trans-W₂Cl₄(NHCMe₃)₂(PEt₃)₂, Pl,a=16.850 (3) Å,b=17.797 (3) Å,c= 11.459 (2)Å,= 101.02 (1),= 103.13°, y=84.23 (1)°,Z=4,V= 3279 (1) Å5,trans-W₂Cl₄(NHCM₃)₂(PMe₂Ph)₂, Fdd2,a=39.563 (8) Å at 20°C; 39.325 (10) Å at -6O°C,b = 57.543 (17) Å at 20°C; 57.186 (16) Å at -60°C,c= 8.810 (1) Å at 20°C; 8.770 (1) Å at - 60°C ,Z=24,V=20057 (7) ų (20°C), 19723 (8) ų ( - 60°C) .6,trans-W₂Cl₄(NHCMe_{3 2}(PPrⁿ ₃)₂, Pl,a= 17.287 (2) Å (20°C); 17.077 (5) Å (-60°C),b= 19.119 (2) Å (20°C); 18.952 (6) Å (-60°C),c= 12.713 (1) Å (20°C); 12.668 (4) Å (-60°C),Z=4,V= 3980 (1) ų (20°C), 3898 (2) ,ų ( - 60°C). In addition, the structure of3a was re-determined and refined so that the disorder ratio was a refined parameter, leading to a value of 0.520:0.480 instead of being arbitrarily fixed at 0.50:0.50. In all of the structures the molecules are held in eclipsed (but very distorted) rotational conformations and the W-W distances are all within the range of 2.305-2.330 Å. As will be shown in a later paper, for all phosphines, thecis andtrans isomers are of similar stability and an equilibrium mixture exists in solution. It is also shown that1a and3a do not contain unexpectedly short W-N bonds as previously reported.     

Neptunium(IV) Complex with Carbamide [Np(Urea)8]SiW12O40 · 2Urea · H2O: Synthesis,Crystal Structure,and Properties

The synthesis and crystal structure of [Np(Urea)₈]SiW₁₂O₄₀ · 2Urea · H₂O complex are reported. Crystallographic parameters: space groups C2/c, a = 18.972(5) Å, b = 18.891(5) Å, c = 16.654(4) Å, = 100.847(6)°, Z = 4, V = 5862(3) ų, (calcd) = 4.226 g/cm³. Thermal properties of this compound are studied; absorption spectra in the IR and visible regions are measured.     

Zur Kristallstruktur von α-TlSmW2O8

Single crystals of -TlSm(WO₄)₂ were examined by X-ray diffractometer technique (space group C _2h ⁶ -C2/c;a=10.770,b=10.597,c=7.597 Å, =130.09°,Z=4). The coordination of W⁶⁺, Sm³⁺ and Tl⁺ are discribed and discussed.-TlSm(WO₄)₂ is isotypic to -KY(WO₄)₂.

     

Thiourea N- and S-Derivatives as Ligands: Synthesis and Crystal Structure of 4CuCl · 6All–NHCSNH2 and [(All–NH)2C–SC2H5]Cu2ClxBr3 – x (x = 0.765, All is Allyl)

Crystals of the compounds 4CuCl · 6CH₂=CH–CH₂–NHCSNH₂ (I) and [(CH₂=CH–CH₂–NH)₂C–SC₂H₅]Cu₂Cl _x Br_{3 – x} (x = 0.765) (II) were synthesized by the ac electrochemical method, and their crystal structures were determined (CuK and MoK radiation, 2575 and 1090 unique reflections with F 4(F), R = 0.050 and 0.028 for I and II, respectively). Complex I crystallizes in space group C2/c, a = 17.230(7) Å, b = 12.258(5) Å, c = 42.95(2) Å, = 97.48(4)°, V = 8994(7) ų, Z = 8. The structure of -complex II is described by space group P2₁/n, a = 10.633(5) Å, b = 9.280(5) Å, c = 16.024(4) Å, = 102.16(3)°, V = 1546(1) ų, Z = 4. Complex I is built from isolated units of the aforementioned composition; every allylthiourea molecule coordinates two metal atoms through the sulfur atom. The distorted tetrahedral surrounding of every Cu(I) atom involves three S atoms and one Cl atom. The N,N"-diallyl-S-ethylisotiouronium cation coordinates two copper atoms through the C=C bonds, 1.32(1) and 1.35(1)Å, uniting the cuprohalide chains in layers. The structure of complex II is very close to the structure of the previously studied -complex of diallylammonium [H⁺L]Cu₂Cl₃.     

Crystal and molecular structure of 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane: Energy and structural relationships for this tetraazamacrocycle in its neutral and protonated forms

The X-ray crystal structure of 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane has been determined. The neutral ligand crystallises in the triclinic space groupP with unit cell parametersa=8.467(4),b=10.057(5),c=10.637(5) Å, =67.68(3), =75.38(4), =76.34(4)°,V=800.75 ų andD _c=1.063 g cm^–3 forZ=2.R=0.047 for 2140 unique observed (I/(I)2.0) reflections (R _w=0.052). Two crystallographically independent molecules are observed. Both are centrosymmetric and adopt a mesodentate conformation. Molecule (1) is identified as the (R, S, S, R)-[trans-IV] isomer and molecule (2) as the (R, R, S, S)-[trans-III] isomer. Molecular mechanics calculations provide a basis for understanding the structural and energetic relationships between the neutral and protonated forms of this tetraazamacrocyclic ligand. Supplementary Data relating to this article have been deposited with the British Library at Boston Spa, Wetherby, West Yorkshire, U.K. as Supplementary Publication No. 82149 (13 pages).     

Reaction of trimethylaluminum with crown ethers. III. The synthesis and crystal structure of (12-crown-4)bis(trimethylaluminum)

The crown ether 12-crown-4 reacts with trimethylaluminum in toluene to form the complex [AlMe₃]₂[12-crown-4]. Attempts to utilize the remaining two oxygen atoms for coordination to AlMe₃ molecules were unsuccessful. The 21 complex crystallizes in the monoclinic space groupP2₁/n witha=11.342(7),b=12.941(4),c=6.973(6) Å, and =95.48(4)°. Refinement led to a finalR value of 0.047 for 925 observed reflections. The molecule resides on a crystallographic center of inversion, and as required by symmetry, the four oxygen atoms are planar. The Al–O bond is strong as revealed by the bond length of 1.977(3) Å. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82013 (9 pages).     

Organotitanium chemistry 12. Synthesis of some new chiral cyclopentadienyl titanium and zirconium complex. The crystal structure of (S-cyclo-C4H7OCH2Cp)2TiCl2

Summary New chiral cyclopentadienyl-titanium and-zirconium complexes Cp₂TiCl₂, CpCpTiCl₂ and Cp₂ZrCl₂ (Cp=⁵ -cyclopentadienyl and Cp=substituted cyclopentadienyl), have been synthesized. The (S,S)-3 complex, which forms red plate crystals, has been studied by x-ray analysis. It belongs to the monoclinic space groupC2, witha 23.963(3),b 6.6470(6),c 12.6618(9) Å, 103.089(7)°, V=1964.4(3) ų and Z=4. The structure was relined to an R factor of 0.048 for 868 observed reflections.     

Comparison of the crystal structures of Co2(X 2O7)·2H2O,X=P and As

Summary Crystals of Co₂(X ₂O₇)·2H₂O,X=P/As were synthesized under hydrothermal conditions. Their crystal structures were determined by single crystal X-ray diffraction:a=6.334(1)/6.531(2),b=13.997(2)/14.206(4),c=7.637(1)/7.615(2)Å, =94.77(2)/94.74(2)°, space group P2₁/n,R=0.032/0.046,R _w=0.028/0.034 for 2423/2042 reflections and 131/119 variables. Within the twoXO₄ tetrahedra connected via a common corner to anX ₂O₇ group the average P-O bond lengths are approximately equal (1.540 and 1.543 Å), but As-O differs significantly (1.685 and 1.696 Å). A comparison with the isotypic Mn and Mg pyrophosphates shows a correlation between the ratio Me-O/X-O and the angle O-X-O.

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Vergleich der Kristallstrukturen von Co₂(X ₂O₇)·2H₂O,X=P und As

Zusammenfassung Kristalle von Co₂(X ₂O₇)·2H₂O,X=P/As wurden unter Hydrothermalbedingungen synthetisiert. Ihre Kristallstrukturen wurden mittels Röntgenbeugung an Einkristallen bestimmt:a=6.334(1)/6.531(2),b=13.997(2)/14.206(4),c=7.637(1)/7.615(2) Å, =94.77(2)/97.74(2)°, Raumgruppe P2₁/n,R=0.032/0.046,R _w=0.028/0.034 für 2423/2042 Reflexe und 131/119 Variable. In den beiden über eine gemeinsame Ecke zuX ₂O₇-Gruppen verknüpftenXO₄-Tetraedern sind die mittleren P-O-Abstände ungefähr gleich (1.540 und 1.543 Å), hingegen differiert As-O signifikant (1.685 und 1.696 Å). Ein Vergleich mit den isotypen Mn- und Mg-Pyrophosphaten zeigt eine Korrelation zwischen dem Quotienten Me-O/X-O und dem WinkelX-O-X.

     

Synthesis and X-ray structural analysis of a unique Co-crystallization complex of [NaSal]2DB24C8 and [KSal]2DB24C8

Sodium salicylate (NaSal where Sal=2-hydroxybenzoate), when mixed with dibenzo-24-crown-8 (DB24C8) yields a bimetallic complex [NaSal]₂DB24C8 in most polar organic media, while potassium salicylate (KSal) under similar conditions shows a tendency to yield 11 or 21 complexes depending upon medium or synthesis. However, the presence of both NaSal and KSal together results in a unique mixed cation complex of composition NaKSal₂DB24C8. This product melts sharply (190-92°C) without decomposition, displays IR spectral characteristics comparable to those of [Na(Sal)]₂DB24C8, and is stable in aqueous media as shown by the detectable cation effect on the UV absorption bands of Sal and DB24C8. Single crystal X-ray analysis of NaK(Sal)₂DB24C8 reveals that the system represents a co-crystallization complex of individual (KSal)₂DB24C8 and (NaSal)₂DB24C8 molecules. The crystals are monoclinic,P2₁/c,a=19.976(2) Å,b=9.031(1) Å,c=25.541(5) Å,=122.065(9)°, ų,T=298 K,Z=2+2, CuK =1.5418 Å, and 2 (2.5°–100°). FinalR factor for the 3012 observed reflections (F>3) is 0.092. Both the Na₂- and K₂-molecules possess crystallographic centers of symmetry with one metal and its associated anion on each side of the crown ring. However, the conformations of the crowns are very different in the two molecules, with the K₂-crown being nearly planar and the Na₂-crown being quite puckered. Four oxygen atoms from the DB24C8 (KO, 2.680–2.908 Å) and three carboxyl oxygen atoms (KO, 2.472–2.708 Å) from separate salicylate ions coordinate with each potassium. Three oxygens from the crown (NaO, 2.536–2.65 Å) and three carboxyl oxygens (NaO, 2.31–2.563 Å) coordinate with each sodium. The salicylate ions lie on opposite sides and nearly perpendicular (77.2°, Na₂-molecule; 82.7° K₂-molecule) to each crown but coordinate to both of the metal ions within a molecule. The K⁺K⁺ and Na⁺Na⁺ distances in the respective molecules are 3.95 and 3.34 Å. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82044 (18 pages).