http://nopr.niscpr.res.in/handle/123456789/41218 2026-10-08T15:05:30Z 2026-10-08T15:05:30Z Gutman, Ivan http://nopr.niscpr.res.in/handle/123456789/41506 2017-04-27T11:25:58Z 1996-11-01T00:00:00Z

Title: On local aromaticity in phenylenes Authors: Gutman, Ivan Abstract: Local aromaticity in phenylenes (as measured by means of the Kekulé-structure-based local aromaticity index, LAI, is shown to follow a pattern that is strictly reverse of what is found in the associated benzenoid hydrocarbons, the so-called hexagonal squeezes (HS). If a hexagon in the HS has large (resp. small) LAI-value, then the corresponding hexagon in the phenylene has small (resp. large) LAI-value. It is demonstrated that in certain cases the sum of the mentioned two LAIs is a constant, independent of any structural detail of the phenylene or its HS. Page(s): 909-914

1996-11-01T00:00:00Z Shafi, K V P M Sathyanarayana, D N http://nopr.niscpr.res.in/handle/123456789/41505 2017-04-27T11:24:54Z 1996-11-01T00:00:00Z

Title: Extended Huckel molecular orbital calculations on hydroxobridged heterotrinuclear cobalt(lll) complexes Authors: Shafi, K V P M; Sathyanarayana, D N Abstract: EHT calculations on heterotrinuclear cobalt(lll) complexes of the type [Cu{(OH)₂Co(L₄)}₂]⁴⁺ where L₄ denotes (en)₂ or (NH₃)₄, en = ethylenediamine and their component species have been carried out. The results regarding bonding and structure for the trinuclear complexes are compared with those for the monomer components such as [Co(en)₂(OH)₂]⁺, [CO(NH₃)₄(OH)₂]⁺ and [Cu(OH)₄]^2- are discussed. Page(s): 915-919

1996-11-01T00:00:00Z Ulagappan, N Krishnasamy, V http://nopr.niscpr.res.in/handle/123456789/41504 2017-04-27T11:17:40Z 1996-11-01T00:00:00Z

Title: Synthesis and characterization of titanium-aluminophosphate molecular sieves of AFI and AEL topologies Authors: Ulagappan, N; Krishnasamy, V Abstract: Titanium-aluminophosphate molecular sieves (TAPO₄) of AFI and AEL topologies, free of anatase have been synthesised by modified procedure and characterised by XRD, TGA, DTA, Laser-Raman, DRS, FT-IR, ²⁷AI, ³¹P and ¹³C MAS-NMR, SEM and chemical analysis. The synthesised TAPO_4.s are crystalline and pure. The unit-cell constants are found to decrease on substitution of titanium, which occupies tetrahedral position. The chemical analysis and ³¹P MAS-NMR show the presence of traces of P₂O₅ in the channels. Page(s): 920-924

1996-11-01T00:00:00Z Sjövall, Rune http://nopr.niscpr.res.in/handle/123456789/41503 2017-04-27T11:13:35Z 1996-11-01T00:00:00Z

Title: Structural studies of Cs₂(Cd_0.29Hg_0.71)I₄ and Cs₂(Cd_0.34Hg_0.66)I₄ Authors: Sjövall, Rune Abstract: The crystals of two Cs₂(Cd_xHg_1-x)I₄ compounds have been grown from aqueous solution in the molar ratios CsI:CdI₂:HgI₂=4:1:1. They are isomorphous at room temperature and the compositions, according to the structure refinements, are Cs₂(Cd_0.29Hg_0.71)I₄ and Cs₂(Cd_0.34Hg_0.66)I₄ which is confirmed by SEM-EDX analyses. The triple iodides, both crystallizing in monoclinic <i>P2</i>₁<i>./m </i> with average unit cell dimension <i>a </i>= 7.76, <i>b </i>= 8.39, c = 11.03 Å and β = 110.3°, are isostructural with the room temperature phases of CS₂CdI₄, <i>a </i>= 7.827(1), <i>b </i>= 8.397(1), <i>c</i> = 11.050(1) Å,b = 110.76°,and Cs₂HgI_4, <i>a </i>= 7.734(1), <i>b </i>= 8.386(1), c = 11.019(1)Å, β = 110.06°.The (Cd,Hg) atoms are randomly distributed in the crystals and Vegard's law is obeyed. Page(s): 925-929

1996-11-01T00:00:00Z