Zigzag chain structures

MnCu(opba)(DMSO)3 structure, 43 196-197 zigzag chain structure, 43 198-199 MnCuCopbaKHiOlj DMSO, structure, 43 196 Mn[Cu(oxpn)l3 =+, 43 217 MnCulpbaOHXHjOlj magnetization versus temperature, 43 193, 195... 

N2H6)ZrF6 Zigzag chain structure ZrFg BTPs share edges 2.12 25... 

Figure 29 Representation of the tetrameric zigzag chain structure as found in [Mo4(HBpz3)2(0)4(fi-...

This equation leads to a reductio ad absurdum that may provide a significant refinement of the helical conductor model. It will be noted that as the step helices (ya = 180°) approach the absolutely planar zigzag chain structure (ya = /b = 180°) they acquire very large cross sections. The index of helieity approaches a constant value of about 0.385 but the expected residue rotations approach infinity. (See Table 12). This result is, at least intuitively, absurd. 

Both Cpln and CpTl are monomeric in the gas phase, but in the solid they possess a polymeric zigzag chain structure, in which the In (or Tl) atoms and Cp rings alternate, as shown in Fig. 13.6.2(e). 

Black copper(II) thiocyanate turns red-brown on heating, and it is postulated that the product is derived from copper(I) thiocyanate distorted by the inclusion of thiocyanogen in the lattice (395). A zigzag chain structure analogous to AgSCN (492) has been suggested for CuNCS on the basis of their similar infrared spectra (502). 

Seg) takes a zigzag chain structure. Four stretching (300-200 cm region) and three bending (170-120 cm region) vibrations have been reported for this ion [1788]. 

A crystalline phase of sulfur has been synthesized by workers (3, 4, 5, 6, 7) at pressures above 21 kb at temperatures in excess of 210°-240°C. This phase is insoluble in CS2. Lind and Geller (8) showed that this high pressure phase, designated fibrous sulfur, is monoclinic (P2) and consists of right and left handed helices. This helical structure resembles slightly the helicoidal zigzag chain structures of selenium and tellurium at ambient conditions. Fibrous sulfur has several properties characteristic of a modest semiconductor such as a steep negative temperature coeflBcient of resistance and a photoelectric eflFect. It shows also an EPR absorption peak and does not revert at ambient conditions (for up to 4 years) to ordinary octameric sulfur (6,7),... 

Selenium and tellurium have the A8 helicoidal zigzag chain structure at ambient conditions (1). Both show maxima in their melting curves at about 50 kb at 963°K for selenium (32) and at an average p-T of about 12 kb at 743°K (22, 29, 33, 34, 35) for tellurium. These maxima are suspected to be related to the maximum in the melting curve of sulfur at 86 kb at 953°K (12) because at these conditions the sulfur polymorph... 

Figure 8.6. Sketch of the zigzag chain structure in the molecular crystals of hydrogen halides.

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