Search results for "Solid-state"

Solid-State Aggregation of Metallacyclophane-Based MnIICuII One-Dimensional Ladders

2012

Two distinct one-dimensional (1) and two-dimensional (2) mixed-metal-organic polymers have been synthesized by using the "complex-as-ligand" strategy. The structure of 1 consists of isolated ladderlike Mn(II)(2)Cu(II)(2) chains separated from each other by neutral Mn(II)(2) dimers, whereas 2 possesses an overall corrugated layer structure built from additional coordinative interactions between adjacent Mn(II)(2)Cu(II)(2) ladders. Interestingly, 1 and 2 show overall ferri- and antiferromagnetic behavior, respectively, as a result of their distinct crystalline aggregation in the solid state.

Insertion reaction of carbon dioxide into Sn-OR bond. Synthesis, structure and DFT calculations of di- and tetranuclear isopropylcarbonato tin(IV) co…

2006

The reaction of carbon dioxide with the stannane nBu2Sn(OiPr)2 and distannoxane [nBu2(iPrO)Sn]2O leads to the selective insertion into one Sn-OiPr bond generating the corresponding nBu2Sn(OiPr)(OCO2(i)Pr) and nBu2(iPrO)SnOSn(OCO2(i)Pr)nBu2 species. Both compounds are characterised by multinuclear NMR, FT-IR and single-crystal X-ray crystallography. In the solid state, they adopt a dimeric arrangement with bridging isopropoxy and terminal isopropylcarbonato ligands. The X-ray crystal structure of the dinuclear stannane shows that the Sn2O2 ring and the two Sn-OCO2C fragments are nearby coplanar. The same holds for the ladder-type tetranuclear distannoxane. The dimeric structures are also evi…

ChemInform Abstract: Dimeric Resorcin[4]arene Capsules in the Solid State

2012

Supramolecular chemistry research is focused on the study of weak non-covalent intermolecular — that is, supramolecular — interactions as the driving force in self-assembly and molecular recognition. Dimeric resorcin[4]arenes capsules have been a focus of our research for the last 15 years. This review describes the solid state complexation studies of unsubstituted phenolic resorcin[4]arenes and pyrogall[4]arenes towards the formation of dimeric capsules and assemblies using ionic and neutral species as guest molecules and templates. The multitude of different crystal structures obtained during these studies demonstrates the versatile nature of resorcin[4]arenes and pyrogall[4]arenes (2-hyd…

Factors affecting physiology of mycelial growth and mushrooms aroma production in solid state fermentation

1997

L'effet de différentes sources d'azote et du rapport C/N sur la croissance mycélienne et sur l'intensité aromatique dégagée par trois espèces du genre #Morchella$ et d'une espèce du genre #Pleurotus$ a été étudié sur agar puis sur support solide. Les résultats ont été à la base du choix du nitrate de sodium comme source d'azote, du rapport C/N de 10 ainsi que du mycélium de #M. esculenta$ come source potentielle pour la production de l'arôme de morille. L'identification des molécules contribuant à l'arôme réalisée par CPG-SM a révélé de larges différences entre #M. esculenta$ et #P. cornucopiae$. Dans la mesure où l'arôme produit par le mycélium rappelle celui du carpophore, ce résultat con…

Conformational changes in Cmethyl-resorcinarene pyridine N -oxide inclusion complexes in the solid state

2016

Aromatic N-oxides interact with Cmethyl-resorcinarene resulting in marked changes in the conformation of the host resorcinarene. In the solid state, 2- and 3-methylpyridine N-oxides form pseudo-capsular 2 : 2 endo host-guest complexes with Cmethyl-resorcinarene stabilized by C-H⋯π interactions. The Cmethyl-resorcinarene·2-methylpyridine N-oxide complex has a C4v crown conformation, while the Cmethyl-resorcinarene·3-methylpyridine N-oxide complex has a slightly open C2v boat conformation. On the contrary, other para-substituted and benzo-fused pyridine N-oxides form only exo complexes with Cmethyl-resorcinarene. In the exo complexes, the asymmetry of the guest, conformational flexibility and…

Unraveling the packing pattern leading to gelation using SS NMR and X-ray diffraction: direct observation of the evolution of self-assembled fibers

2010

A detailed understanding of the mode of packing patterns that leads to the gelation of low molecular mass gelators derived from bile acid esters was carried out using solid state NMR along with complementary techniques such as powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and polarizing optical microscopy (POM). Solid state 13C{1H} cross polarization (CP) magic angle spinning (MAS) NMR of the low molecular mass gel in its native state was recorded for the first time. A close resemblance in the packing patterns of the gel, xerogel and bulk solid states was revealed upon comparing their 13C{1H}CPMAS NMR spectral pattern. A doublet r…

NMR Spectra of Anilines

2009

1 Introduction 2 Ring and N-Substituted Anilines 3 Multinuclear NMR Studies of p-F-Aniline Derivatives 4 Dynamic NMR of Aniline Derivatives 5 Anilines with Other (Fused) Aromatic Rings 6 NMR Relaxation Studies of Aniline Derivatives 7 Solid State NMR Studies 8 Theoretical Calculations of Aniline NMR Parameters Keywords: aniline NMR spectra; aniline (aminobenzene, phenylamine); ring and N-substituted anilines; dual-substituent-parameter (DSP) analysis; cyclic amine structures; dynamic NMR of aniline derivatives; H NMR spectroscopy as measure of donor strengths; aniline derivative NMR relaxation studies

PROPERTIES AND APPLICATIONS OF POLYAMINOCYCLODEXTRIN DERIVATIVES

Nel presente lavoro sono state prese in esame le potenziali applicazioni delle poliamminociclodestrine. In particolare, diversi derivati poliamminociclodestrinici (amCD) sono stati ottenuti utilizzando un approccio sintetico diretto, tramite reazione di sostituzione nucleofila tra la heptakis-(6-deossi)-(6-bromo)-βCD (BrβCD) e poliammine lineari. Una volta effettuata l’opportuna caratterizzazione NMR, ESI-MS e potenziometrica, sono state investigate diverse possibili utilizzazioni di tali materiali. Anzitutto, sono state valutate le capacità di dare complessi di inclusione host-guest con diversi derivati organici sia delle amCD libere che di materiali costituiti da nanospugne a base di amCD…

Polarization Switching in Heterophase Nanostructures: PLZT Relaxor Ceramics

2005

The polarization switching is experimentally investigated in hot-pressed PLZT-x/65/35 ceramics with a lanthanum content from 5 to 12 at. %. The specific features in the temperature dependence of the polarization switching in a heterophase state are interpreted by analyzing the change in the switched charge measured over wide ranges of fields and temperatures. Particular emphasis is placed on the role of depolarization fields induced by interphase boundaries. A model of the evolution of polydomain nanostructures with a change in the temperature and in the response to an external field is considered. It is assumed that the low-temperature dielectric anomaly and the temperature hysteresis are …

Pt(II) nitrile complexes: New insights on old complexes from a combined experimental and theoretical study

2017

Abstract The spectroscopic characterization of cis - and trans -[PtCl 2 (NCR) 2 ] (R = CH 3 , Ph, CH 2 Ph) was reported in solid state and solution phase. Moreover, the X-ray structures of cis -[PtCl 2 (NCCH 3 ) 2 ], cis - and trans -[PtCl 2 (NCPh) 2 ] were redetermined at low temperature. FT-IR and NMR showed a blue-shift and a slight shielding of the νCN and δ ( 13 C CN ) values, respectively, in a counterintuitive way with respect to the well known improved reactivity towards nucleophiles of nitriles ligands coordinated to platinum(II), when compared to their free forms. These spectroscopic behaviors were also confirmed by theoretical experiments at DFT level. Moreover, DFT approach show…