Search results for "molecular materials"
showing 10 items of 46 documents
Hybrid molecular materials for optoelectronic devices
2005
Hybrid molecular materials based on semiconductor nanocrystalline metal oxides are a subject of intense research for the development of optoelectronic devices. Such devices follow the strategy of combining high surface area mesoporous materials with optically and electrochemically active molecules. Photovoltaic devices, molecular sensors and biosensors are some of the examples discussed in this paper.
Crystal Engineering of Multifunctional Molecular Materials
2007
In this paper we will focus on the crystal engineering of molecular materials exhibiting magnetic and/or electrical properties. The complexity of these materials needs of a precise design of the molecular building blocks, a control of the intermolecular interactions (hydrogen bonds, host/guest interactions, etc.) and a mastery in crystallization techni- ques in order to design crystal structures exhibiting useful physical proper- ties. We will illustrate this concept through some relevant examples based on two-component hybrid materials.
The lower rather than higher density charge carrier determines the NH 3 -sensing nature and sensitivity of ambipolar organic semiconductors
2018
International audience; Despite the extensive studies and great application potentials, the sensing nature of ambipolar organic semiconductor gas sensors still remains unclarified, unlike their inorganic counterparts. Herein, different numbers of thiophenoxy groups are introduced into the phthalocyanine periphery of bis(phthalocyaninato) rare earth semiconductors to continuously tune their HOMO and LUMO energies, resulting in the ambipolar M[Pc(SPh)(8)](2) [M = Eu (1), Ho (2)] and p-type M(Pc)[Pc(SPh)(8)] [M = Eu (3), Ho (4)]. An OFET in combination with direct I-V measurements over the devices from the self-assembled nanostructures of 1-4 revealed the original electron and hole densities (…
The first metamagnetic one-dimensional molecular material with nickel(ii) and end-to-end azido bridges
2001
A novel single azido bridged one-dimensional Ni(II) chain, which represents the first metamagnetic one-dimensional metal–azido system with only end-to-end azido bridges, has been synthesised and characterised by a low temperature magnetic study. Lloret Pastor, Francisco, Francisco.Lloret@uv.es
Recent Advances of Spin Crossover Research
2004
Thermal spin transition (spin crossover), one of the most fascinating dynamic electronic structure phenomena occurring in coordination compounds of third row transition metal ions, mostly of iron(II), iron(III) and cobalt(II) with critical ligand field strengths competing with the spin pairing energy, has attracted increasing attention by many research groups. One of the reasons is the promising potential for practical applications. In this chapter we intend to cover essential recent work, primarily accomplished within the European research network on "Thermal and Optical Switching of Molecular Spin States (TOSS)". New spin crossover compounds and their thermal spin transition behaviour, al…
A Novel Gas Sensor Transducer Based on Phthalocyanine Heterojunction Devices
2007
Abstract: Experimental data concerning the changes in the current-voltage (I-V) perfor-mances of a molecular material-based heterojunction consisting of hexadecafluorinated nickel phthalocyanine (Ni(F 16 Pc)) and nickel phthalocyanine (NiPc), (Au|Ni(F 16 Pc)|NiPc|Al) are introduced as an unprecedented principle of transduction for gas sensing performances. The respective n - and p -type doped-insulator behaviors of the respective materials are supported, owing to the observed changes in surface potential (using the Kelvin probe method) after submission to electron donor (ammonia) and electron acceptor gases (ozone). On the other hand, the bilayer device exhibits strong variations in the bui…
Recent advances in polyoxometalate-containing molecular conductors
2005
The recent advances in crystalline conducting molecular materials based on polyoxometalates (POMs) and organic donors of the tetrathiafulvalene (TTF) family or perylene are discussed. We emphasise the wide diversity of POM structural types and the variety of packing architectures for the organic molecules that can be induced by these inorganic anions. Besides structural effects, we show that these hybrids can have interesting electric and/or magnetic properties. Thus, in the last years the common belief that this type of radical salts containing such big and highly charged anions could only exhibit poor conducting properties has been refuted by the production of new materials exhibiting hig…
Microwave signature for gas sensing: 2005 to present
2015
Abstract We present here the development and the implementation of a technique of gas detection involving a microwave transduction method. The use of low-cost sensors based on microstrip or coplanar structures, adapted to the microwaves domain, allows the sensitive materials deposition under various forms. The purpose of the study is to assess the interest of microwave transduction for gas detection. The choice of the sensitive materials concerns materials widely used in the field of gas sensing: the metal oxides (SnO2 and TiO2) as well as molecular materials like cobalt phthalocyanine (CoPc). In this article we shall apply to explain the principles of the microwave transduction before appr…
Unprecedented multi-stable spin crossover molecular material with two thermal memory channels.
2013
et al.
Clathration of Five-Membered Aromatic Rings in the Bimetallic Spin Crossover Metal–Organic Framework [Fe(TPT)2/3{MI(CN)2}2]·G (MI = Ag, Au)
2014
Six clathrate compounds of the three-dimensional spin crossover metal−organic framework formulated [Fe(TPT)2/3{MI (CN)2}2]· nG, where TPT is 2,4,6-tris(4-pyridyl)-1,3,5-triazine, MI = Ag or Au and G represent the guest molecules furan, pyrrole and thiophene, were synthesized using slow diffusion techniques. The clathrate compounds were characterized by single-crystal X-ray diffraction at 120 and 300 K, thermogravimetric analysis and thermal dependence of the magnetic susceptibility. All compounds crystallize in the R3̅ m trigonal space group. The FeII defines a unique [FeN6] crystallographic site with the equatorial positions occupied by four dicyanometallate ligands while the axial positio…