Effects of substituents X and Y on the NMR chemical shifts of 2-(4-X phenyl)-5-Y pyrimidines

Yuan, Hua; Chen, Peng-Wei; Li, Mengyang; Zhang, Yan; Peng, Zhaowei; Liu, Wanqiang; Paton, Robert S.; Cao, Chenzhong

doi:10.1016/j.molstruc.2019.127489

Cited by 10 publications

(6 citation statements)

References 50 publications

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“…PES programmes in Mozambique, Costa Rica, Ecuador, Uganda, Columbia, China, Brazil, Tanzania and Cambodia each report this factor. There is convergence of data that participants with a higher level of existing income and a more diversified income base are more likely to take up PES programmes (e.g., Beauchamp, 2015;Hedge, 2012;Yuan, 2017).…”

Section: Results Of the Qualitative Synthesismentioning

confidence: 99%

Incentives for climate mitigation in the land use sector—the effects of payment for environmental services on environmental and socioeconomic outcomes in low‐ and middle‐income countries: A mixed‐methods systematic review

Snilsveit¹,

Stevenson²,

Langer

et al. 2019

Campbell Systematic Reviews

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Unsustainable practices in the land use sector contribute to climate change through the release of greenhouse gases. Payment for environmental services (PESs) provide economic incentives to reduce the negative environmental impacts of land use and are a popular approach to mitigate climate change in low‐ and middle‐income countries. Some PES programmes also aim to improve socioeconomic outcomes and reduce poverty. This systematic review examines the effect of programmes on environmental and socioeconomic outcomes. We identified 44 quantitative impact evaluations and 60 qualitative studies of PES programmes for inclusion in the review, to assess both the effects of PES and identify context, design and implementation features that may influence PES effectiveness. The studies covered 18 programmes from 12 countries in Latin America and the Caribbean, East Asia and Pacific, South Asia and Sub‐Saharan Africa. The review finds that PES may increase household income, reduce deforestation and improve forest cover, but the findings are, however, based on low and very low quality evidence from a small number of programmes and should be treated with caution. Qualitative evidence indicates that several factors influence whether PES programmes are likely to be effective in different contexts and suggests that the inclusion of strong governance structures and the effective targeting of both locations and participants may improve intervention effectiveness. Funders, implementing agencies and researchers should collaborate to develop a coordinated programme of rigorous, mixed‐methods impact evaluation implemented across contexts. Until such evidence is available, PES programmes remain a high‐risk strategy for climate change mitigation.

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Section: Results Of the Qualitative Synthesismentioning

confidence: 99%

Incentives for climate mitigation in the land use sector—the effects of payment for environmental services on environmental and socioeconomic outcomes in low‐ and middle‐income countries: A mixed‐methods systematic review

Snilsveit¹,

Stevenson²,

Langer

et al. 2019

Campbell Systematic Reviews

View full text Add to dashboard Cite

show abstract

“…Excited-state substituent parameter (σ ex CC ) was proposed by Cao et al [23] and is a molecular descriptor characterizing the stability of the excited state. It was extensively applied to the QSPR studies [29,[33][34][35] and plays an important role in the study of the chemical shifts. [33,36,37] We use both OH and CH N as reference and express the σ ex CC of the substituent X as σ ex CC X ð Þ OH and σ ex CC X ð Þ CH N by adopting the locating method of substituent X in Section 2.3.2, listed in Table 1.…”

Section: Excited-state Substituent Parameters (σ Ex CC )mentioning

confidence: 99%

Influences of polarizability effect of alkyl group and homoring competition effect of substituents on the NMR spectra of salen‐type Schiff base

Wei¹,

Cao²

2021

Magnetic Reson in Chemistry

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Salen-type Schiff bases are a kind of important compounds and are widely used. In order to explore the effect of alkyl groups and substituents attached to aromatic ring on the chemical shifts, 63 title compounds were synthesized.Their 1 H NMR and 13 C NMR spectra were obtained; and the effects of the alkyl chain length and substituents on the chemical shifts (δ H (CH N), δ C (CH N), δ H (OH), and δ C (C OH)) were studied. The results show that (1) the alkyl polarizability effect index (PEI) has an important influence on the chemical shifts of the above four atoms, with the increase of PEI, the values of δ H (CH N) and δc(CH N) decrease, and the values of δ H (OH) and δ C (C OH) increase. (2) The influence of substituent X attached to aromatic ring on the chemical shift is related to its position by taking OH or CH N as reference. As for the effect of substituent on the chemical shifts, the effect of Hammett constant σ(X) OH and excited-state substituent parameter σ ex CC X ð Þ OH with OH as reference are different from that ofσ(X) CH N and σ ex CC X ð Þ CH N with CH N as reference, and there is a "homoring competition effect" of the substituent.(3) The effect of the cross-interaction between X and OH on the chemical shift is also significantly different due to the different position of X. Quantitative correlation equations against chemical shifts were built for the four atoms, and the stability and prediction ability of the obtained equations were confirmed by leave-one-out cross validation.

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“…It can also be used as a supporting material to prevent the liquid leakage of solid–liquid PCMs because of its unique worm‐like structure with a large volume and many pores. EG has a large surface area, high surface activity, and good compatibility with organic and inorganic PCMs . Zhang et al prepared paraffin/EG composite PCMs by absorbing paraffin into EG.…”

Section: Encapsulation Of Solid–liquid Pcmsmentioning

confidence: 99%

Latent Heat Thermal Energy Storage Systems with Solid–Liquid Phase Change Materials: A Review

Zhang¹,

Yuan²,

Cao³

et al. 2018

Adv Eng Mater

366

108

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This paper provides a review of the solid-liquid phase change materials (PCMs) for latent heat thermal energy storage (LHTES). The commonly used solid-liquid PCMs and their thermal properties are summarized here firstly. Two major drawbacks that seriously limit the application of PCMs in an LHTES system, that is, low thermal conductivity and liquid leakage, are discussed. Various methods for enhancing the thermal conductivity and heat transfer of solid-liquid PCMs are explained. Previous studies regarding formstable composite PCMs and microencapsulated PCMs are also presented. Furthermore, applications of the solid-liquid PCMs used in LHTES and thermal management systems are introduced and analyzed. Finally, future outlooks and research topics are proposed.

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Effects of substituents X and Y on the NMR chemical shifts of 2-(4-X phenyl)-5-Y pyrimidines

Cited by 10 publications

References 50 publications

Incentives for climate mitigation in the land use sector—the effects of payment for environmental services on environmental and socioeconomic outcomes in low‐ and middle‐income countries: A mixed‐methods systematic review

Incentives for climate mitigation in the land use sector—the effects of payment for environmental services on environmental and socioeconomic outcomes in low‐ and middle‐income countries: A mixed‐methods systematic review

Influences of polarizability effect of alkyl group and homoring competition effect of substituents on the NMR spectra of salen‐type Schiff base

Latent Heat Thermal Energy Storage Systems with Solid–Liquid Phase Change Materials: A Review

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