X-ray single-crystal analysis

In addition to the above oxides M2O, M2O2, M4O6, MO2 and MO3 in which the alkali metal has the constant oxidation state 4-1, rubidium and caesium also form suboxides in which the formal oxidation state of the metal is considerably lower. Some of these intriguing compounds have been known since the turn of the century but only recently have their structures been elucidated by single crystal X-ray analysis. Partial oxidation of Rb at low temperatures gives RbeO which decomposes above —7.3°C to give copper-coloured metallic crystals of Rb902 ... 

The unexpectedly complex product was isolated as an almost colourless air-stable powder, and a single-crystal X-ray analysis showed that it had the molecular adamantane-like structure (5). This is very similar to the structure of the iso-electronic compound P4O10 (p. 504). 

The translucent, cream-coloured benzene solvate was characterized by single-crystal X-ray analysis and by Pnrnr spectroscopy. The first free phospha-alkyne stable to polymerization... 

In some sulfur extrusions from 2,7-di-/ Tt-butylthiepins a byproduct containing two sulfur atoms is obtained, along with the aromatic compound. The byproduct has been characterized as a thienothiophene by single crystal X-ray analysis.92... 

Zareba et al. [165] described the crystal structure of the chiral 4-(l-methyl-heptyloxycarbonyl)-phenyl 4-heptyloxytolane-4 -carboxylate (C7-tolane) which shows monotropic antiferroelectric and ferroelectric phases. The single-crystal X-ray analysis of this compound shows that the crystal has a smectic-like layer structure composed of largely bent molecules where the chain of the chiral group is almost perpendicular (86°) to the core moiety. Within the layers, the molecules are tilted. The central tolane group of the molecule is roughly planar. 

Stoichiometric reaction of 5 with phenylsilane produced the iron(O) bis(silane) c-complex 18, which was confirmed by the single-crystal X-ray analysis as well as SQUID (Superconducting QUantum Interference Device) magnetometry (Scheme 19). Complex 18 as a precatalyst showed high activity for the hydrosilylation of 1-hexene. 

Selected area diffraction (SAD) combined with microscopy is an important supplementary tool to X-ray diffraction in crystal structure analysis. SAD has the additional advantage of giving the correlation between morphology and crystal structure whenever single crystals are too small for single-crystal X-ray analysis. 

Powder diffraction x-ray analysis and DSC are the methods most often used to distinguish between different polymorphs. Single crystal x-ray analysis [24] will give information about the position of molecular groups within the crystal and thus actually defines the... 

A single-crystal X-ray analysis of the triphenylphosphine complex [Ni(PPh3)(CS2)]2 has revealed that the complex has the binuclear structure (1017). The complex [Ni(PMe3)2(CS2)2] displays NiPSCS coordination (1018) and is severely distorted from square planar. Of interest is the fact that the SC(S)SC(PMe3)S linkage can be formally described as a condensation product of two molecules of CS2 with one molecule of PMe3.2464... 

Single crystal X-ray analysis of the pyrimido[2,l-3][l,3]thiazine 293 was performed to verify the structure and the regioselectivity of the synthesis from diazadiene <2002S403>. 

Single crystal X-ray analysis definitively assigned different structures to products of oxidative cyclization of 58 as pyrazolo 1,2-/z][ l,2]diazepin-5(3//)-onc 59 <1984ZNB187> and pyrazolo[l,2-tf]pyrazol-l(5//)-onc 60 <1997ZNB994>, depending on the character of the R2 substituent. 

Attempts to determine the relative stereochemistry of the carboxamide substituent at the C-9 stereocenter of 64a using various H NMR experiments failed. However, the structure of the compound 64a was unambiguously assigned by single-crystal X-ray analysis <2004JOC1207>. 

The structure of compound 18a (Table 2) has also been unambiguously settled by single-crystal X-ray analysis <20050L5301>. 

When the potassium derivative was allowed to stand in ammonia, single crystals of the diammoniate K2[Zn(C2Fl)4]-2NFl3 63 separated.120 A low-temperature, single crystal X-ray analysis of 63 showed it to consist of tetrahedral [Zn(C2H)4]2 ions, which feature almost linear Zn-C-C units. The zinc-carbon bonds (2.053(3) A) are slightly longer than those in 64, while the carbon-carbon bonds are identical (1.203(4) A) in length. 

Diethylzinc reacted with 1 equiv. of sulfur in toluene to furnish a colorless crystalline compound with the empirical formula EtZnSEt 161, whose structure was revealed by single crystal X-ray analysis as that shown in Figure 74.226... 

---