The Magnitude and Mechanism of Charge Enhancement of CH∙∙O H-bonds

Quantum calculations find that neutral methylamines and thioethers form complexes, with N-methylacetamide (NMA) as proton acceptor, with binding energies of 2–5 kcal/mol. This interaction is magnified by a factor of 4–9, bringing the binding energy up to as much as 20 kcal/mol, when a CH3+ group is added to the proton donor. Complexes prefer trifurcated arrangements, wherein three separate methyl groups donate a proton to the O acceptor. Binding energies lessen when the systems are immersed in solvents of increasing polarity, but the ionic complexes retain their favored status even in water. The binding energy is reduced when the methyl groups are replaced by longer alkyl chains. The proton acceptor prefers to associate with those CH groups that are as close as possible to the S/N center of the formal positive charge. A single linear CH··O hydrogen bond (H-bond) is less favorable than is trifurcation with three separate methyl groups. A trifurcated arrangement with three H atoms of the same methyl group is even less favorable. Various means of analysis, including NBO, SAPT, NMR, and electron density shifts, all identify the +CH··O interaction as a true H-bond

Crowdsourcing in business and management disciplines: an integrative literature review

The objective of this study is to review crowdsourcing literature of the business and management disciplines and to know its relation with the open innovation concept. A systematic literature review is used in this study. Studies on crowdsourcing are published mostly in recent years, 2011-2013. Studies are highly dispersed, published in a very wide range of journals and are mostly based on a single case as data source. Content analysis of the findings of articles are performed to synthesize the findings in the extant literature. Most of the qualitative articles used single case method and most of the quantitative studies relied on online survey over a single crowdsourcing platform. Studies and scholars in the literature are from a limited number of countries. Although crowdsourcing as a concept overlaps with the open innovation concept, by no means, it can be considered a concept under the broad umbrella of open innovation concept. Based on identified gaps, future research avenues are presented