An intermediate neglect of differential overlap technique for spectroscopy of transition-metal complexes. Ferrocene
01 Jan 1980-Journal of the American Chemical Society (American Chemical Society)-Vol. 102, Iss: 17, pp 589-599
About: This article is published in Journal of the American Chemical Society.The article was published on 1980-01-01. It has received 1130 citations till now. The article focuses on the topics: Ferrocene & ZINDO.
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TL;DR: In this paper, the development of efficient light conversion molecular devices (LCMDs) based on lanthanide complexes is reviewed, with emphasis on the work of our group, who have adopted a strategy based upon both theoretical and experimental (synthesis and methodological) investigations.
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TL;DR: In this contribution to the special software-centered issue, the ORCA program package is described, which is a widely used program in various areas of chemistry and spectroscopy with a current user base of over 22 000 registered users in academic research and in industry.
Abstract: In this contribution to the special software-centered issue, the ORCA program package is described. We start with a short historical perspective of how the project began and go on to discuss its current feature set. ORCA has grown into a rather comprehensive general-purpose package for theoretical research in all areas of chemistry and many neighboring disciplines such as materials sciences and biochemistry. ORCA features density functional theory, a range of wavefunction based correlation methods, semi-empirical methods, and even force-field methods. A range of solvation and embedding models is featured as well as a complete intrinsic to ORCA quantum mechanics/molecular mechanics engine. A specialty of ORCA always has been a focus on transition metals and spectroscopy as well as a focus on applicability of the implemented methods to "real-life" chemical applications involving systems with a few hundred atoms. In addition to being efficient, user friendly, and, to the largest extent possible, platform independent, ORCA features a number of methods that are either unique to ORCA or have been first implemented in the course of the ORCA development. Next to a range of spectroscopic and magnetic properties, the linear- or low-order single- and multi-reference local correlation methods based on pair natural orbitals (domain based local pair natural orbital methods) should be mentioned here. Consequently, ORCA is a widely used program in various areas of chemistry and spectroscopy with a current user base of over 22 000 registered users in academic research and in industry.
1,308 citations
TL;DR: The development of air-stable n-channel organic semiconductors with improved performance in organic thin film transistors (OTFTs) is a major challenge for materials chemists as discussed by the authors.
Abstract: The development of new organic semiconductors with improved performance in organic thin film transistors (OTFTs) is a major challenge for materials chemists. There is a particular need to develop air-stable n-channel (electron-conducting) organic semiconductors with performance comparable to that of p-channel (hole-conducting) materials, for organic electronics to realize the benefits of complementary circuit design, i.e., the ability to switch transistors with either positive or negative gate voltages. There have been significant advancements in the past five years. In terms of standard OTFT metrics such as the field effect mobility (μFET) and on-to-off current ratio (ION/IOFF), n-channel OTFTs have achieved performance comparable both to that of n-channel amorphous silicon TFTs and to that of the best reported p-channel (hole-conducting) OTFTs; however, issues of device stability linger. This review provides a detailed introduction to OTFTs, summarizes recent progress in the development of new n-channel...
1,293 citations
TL;DR: It is shown that the amplitude of the transfer integrals is extremely sensitive to the molecular packing, and specific arrangements can lead to electron mobilities that are larger than hole mobilities, which is, for instance, the case of perylene.
Abstract: Organic semiconductors based on π-conjugated oligomers and polymers constitute the active elements in new generations of plastic (opto)electronic devices. The performance of these devices depends largely on the efficiency of the charge-transport processes; at the microscopic level, one of the major parameters governing the transport properties is the amplitude of the electronic transfer integrals between adjacent oligomer or polymer chains. Here, quantum-chemical calculations are performed on model systems to address the way transfer integrals between adjacent chains are affected by the nature and relative positions of the interacting units. Compounds under investigation include oligothienylenes, hexabenzocoronene, oligoacenes, and perylene. It is shown that the amplitude of the transfer integrals is extremely sensitive to the molecular packing. Interestingly, in contrast to conventional wisdom, specific arrangements can lead to electron mobilities that are larger than hole mobilities, which is, for instance, the case of perylene.
1,145 citations
TL;DR: In this paper, the electron-hole pair created via photon absorption in organic photoconversion systems must overcome the Coulomb attraction to achieve long-range charge separation, and this process is facilitated through the formation of excited, delocalized band states.
Abstract: The electron-hole pair created via photon absorption in organic photoconversion systems must overcome the Coulomb attraction to achieve long-range charge separation. We show that this process is facilitated through the formation of excited, delocalized band states. In our experiments on organic photovoltaic cells, these states were accessed for a short time (
1,023 citations