Tetragonal pyramidal structure

Transannular interaction via the electron-delocalization mechanism was found, but lessened by 10-15% for the ligand superhyperfine splitting and 30-35% for the hyperfine splitting (62) in the epr spectrum. The crystal structure of [VOS2CNEt2)2] shows that the molecular core has the expected C2V symmetry [V-0 = 159.1(4), V-S = 138.7(2)-241.0(2) pm] (63). Magnetic and spectral data provided evidence for a tetragonal, pyramidal structure (VII) for these complexes. Like many other coordinatively unsaturated, metal... 

Pentaborane(9) is a volatile, colorless liquid, m.p. —46.9 °C, b.p. 60.1 °C, which ignites in contact with air. It is fairly stable hydrolytically, but reacts rapidly with hot water. It has a tetragonal pyramidal structure with four 3c2e BHB bridge bonds at the basal boron atoms. 

For the equatorial C—P—C bond angles, however, larger deviations from their ideal 120° values are found. Whether these alone, without concomitant comparable alterations of the axial C—P—C angles, ran justify the definition of a gradual distortion towards a specific tetragonal-pyramidal structure might be questioned. On the basis of a proper evaluation of more latent structural features, as done in... 

The infrared spectrum (KBr) shows an absorption in the hydride region at 2040 cm-1. The H nmr spectrum in benzene at 20° shows the Rh—H resonance as a doublet of quintets centered around t28.4. The same nmr pattern has been reported7 for HRh(CH3PPh2)4 and was attributed to a tetragonal pyramid structure, although this has been questioned.8... 

In an early study by Lehn et al., it was also demonstrated that quaterpyridine (36) forms a monomeric copper(I) species (that is not helical), whereas with cop-per(II) a dimeric species is obtained these complexes may be interconverted elec-trochemically. The above monomeric copper(I) complex was shown by X-ray diffraction to have a tetragonal pyramidal structure [four basal nitrogens and an axial oxygen (water)] in the solid state. This ligand also yields a dinuclear complex with ruthenium(II) of type [Ru2L2] . ... 

The use of B stirring techniques (7) has not only confirmed 64) the tetragonal pyramidal structure including the ratio of bridge to terminal hydrogens, but has further indicated that the apex boron atom... 

A tetragonal pyramidal structure (C symmetry) with the above parameters was used by Begun et al. (2) in the analysis of the... 

The infrared and Raman spectra (j, 1 ) of the solid adduct CsF SF are consistent with a slightly distorted tetragonal pyramidal structure for the SF,." anion. We adopt this configuration assuming the length of the four equivalent bonds is the same... 

The compound Fe5(CO)isC is produced in small quantity when Fe3(CO)j2 is heated in petroleum ether with methylphenylacetylene. It has the tetragonal pyramidal structure shown in Fig. 22.11(a), in which C is located just below the... 

The 29Si NMR spectra of (138), where M = Ga, In, R = SiMe Bu2, are consistent with preferential localisation of negative charge on the terminal silicon atom.641 The 1-D and 2-D 111 NMR studies on the indium(III)-bleomycin A2 (InBLM) show that the BLM is coordinated to In(III) through five N atoms, to give a distorted tetragonal pyramidal structure.642... 

The XeFs anion has 12 normal vibrations, which are classified into A ](R)+A2(IR)+2 j(IR)+2 2(R)+ 2 (inactive) under D5/, symmetry. Thus, only three vibrations (A 2 and 2Il ) are IR-active and only three vibrations (A +2 2) are Raman-active. In agreement with this prediction, the observed Raman spectmm of (CH3)4N[XeF5] exhibits three bands at 502 (symmetric stretch, A j), 423 (asymmetric stretch, E 2), and 377 cm (in-plane bending, As discussed in Sec. 1.11, the trigonal-bipyramidal and tetragonal-pyramidal structures can be ruled out since many more IR- and Raman-active bands are expected for these structures. 

SbCls is a weak electron pair donor but an excellent acceptor and many complexes of SbCH with donor molecules L are known.There are complexes of the types LSbCH or LsSbCls with bisphenoidal or tetragonal pyramidal structures respectively. Addition of CD to SbCls gives bisphenoidal... 

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