Single crystal X-ray molecular structure

To date, six single-crystal X-ray molecular structures of alkynyliodonium compounds have been reported four aIkynyl(phenyl)iodonium salts including the substituted cyanoethynyl salt, one heterocyclic and one dialkynyliodonium salt, all with oxyanions. Key structural data for these compounds are summarized in Table 3-1. 

Fig. 13 Two different views of single-crystal X-ray molecular structure of complexes CPh2-n -Ci3H8)MCl2 M = Zr (6), Hf (7)...

The single-crystal X-ray molecular structure of the complex p-(Me2Si) (3,6di- BuFlu)( BuN)TiCl2 10, is depicted in Fig. 17. It shows a striking similarity to crystal structure of complex 9 with respect to its overall symmetry, despite the exchange of one of the aromatic rings, the cyclopentadienyl, in the molecule and its replacement with an amido group. Complex 10 exemplifies one of the rare examples of a titanium-based syndiotactic-specific metallocene catalyst systems. 

Fig. 26 Single-crystal X-ray molecular structures of (q -C5H4-n-CPh2-n -3- Bu-Ci3H6)Zi02,12 (right) and (ti -3- Bu-C5H3-ir-CPli2-n -Ci3H7)ZrCl2,13 (left)...

Figure 8.26 Schematic formula (a) molecular single crystal X-ray diffraction structure (b), and solid state packing (c) ofthe cationic gold complex [Au bimy(Ci6H33) 2]Br H20. (Reproduced from Ref [52] by permission.)...

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). 

Single crystal x-ray diffraction is, without doubt, one of the most important techniques for the determination of molecular structures in the solid state. The technique is also pivotal to the determination of accurate bond lengths in molecules. However, the analysis of x-ray... 

The elucidation of the structure of the phthalocyanines followed some pioneering research into the chemistry of the system by Linstead of Imperial College, University of London. The structure that we now recognise was first proposed from the results of analysis of a number of metal phthalocyanines, which provided the molecular formulae, and from an investigation of the products from degradation studies. Finally, Robertson confirmed the structure as a result of one of the classical applications of single crystal X-ray crystallography. 

The structures of compounds 55a,c and 56a,c were established by means of NMR spectroscopy and mass spectrometry. Due to the different polarity of the C=N and C=P triple bonds, the silicon ring atom in 55a,c is bound to the nitrogen atom, and in 56a,c to the carbon atom of the C=P moiety. The molecular structure of 55a was further determined by single-crystal X-ray diffraction analysis (Fig. 16).14 The four-membered SiNAsC framework is slightly puckered (folding angle N—Si—C/Si—C—As 7°), and... 

A single crystal X-ray structure analysis of 8 (Fig. 4) confirms the molecular constitution of the compound deduced by spectroscopic methods and shows further structural details. The molecule is dimeric with a Mn-C15 ( -carbyne) bond length of 1.857(2) A and a Mn-Mn bond distance of 2.565(1) A the latter one is typical for a Mn-Mn single bond [13]. The Mn-C15 (carbyne) bond is short compared to known Mn-C single bonds, for example that in (OC)4Mn-C(C00Et)C(HgBr)C(0Et)0 is found to be 2.051(26) A [13b], For the acyclic carbyne complex [Cp(CO)2Mn = C-CH=CPh2]+ BF4 the MnC distance is 1.665(5) A [14] comparable values for... 

With the rapid development of modem analysis techniques, especially the popularization of single-crystal X-ray diffraction equipment, the origin of various physical and chemical properties, and the clear elucidation of correlations between the structure and properties of Pcs have become possibilities. Together with the maturity and diversification of their modifications, many Pcs have been synthesized and their molecular structures characterized by X-ray diffraction analysis in the past 5 years [15-77]. 

The molecular structure of both 1,2,5-thiadiazole 1 and 2,1,3-benzothiadiazole 2 were described in CHEC(1984) <1984CHEC(6)513>. Since the publication of CHEC-II(1996) <1996CHEC-II(4)355>, a large number of single crystal X-ray structures have been published for various monocyclic, fused, and related thiadiazoles. 

Compound A was obtained from a reaction of tetrakis(2,6-diethylphenyl)digermene with an excess of DMSO in toluene. The molecular structures of both A and B were determined by single-crystal X-ray analyses (Figure 27). 

Another characteristic point is the special attention that in intermetallic science, as in several fields of chemistry, needs to be dedicated to the structural aspects and to the description of the phases. The structure of intermetallic alloys in their different states, liquid, amorphous (glassy), quasi-crystalline and fully, three-dimensionally (3D) periodic crystalline are closely related to the different properties shown by these substances. Two chapters are therefore dedicated to selected aspects of intermetallic structural chemistry. Particular attention is dedicated to the solid state, in which a very large variety of properties and structures can be found. Solid intermetallic phases, generally non-molecular by nature, are characterized by their 3D crystal (or quasicrystal) structure. A great many crystal structures (often complex or very complex) have been elucidated, and intermetallic crystallochemistry is a fundamental topic of reference. A great number of papers have been published containing results obtained by powder and single crystal X-ray diffractometry and by neutron and electron diffraction methods. A characteristic nomenclature and several symbols and representations have been developed for the description, classification and identification of these phases. 

The molecular structures of both complexes [Mn(bmip)(CO)3] (45) and [Re(bmip)(CO)3] (46) were revealed by single-crystal X-ray determination (Figs. 31a and 31b). 

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