A new mixed-valence cyanide-bridged complex, Br3Fe（p-NC）RuBr（dppm）2 （dppm = bis（diphenylphosphino）methane）, was obtained through the reaction between trans-（dppm）2C1- RuCN and FeBr3. Its crystal structure wa...A new mixed-valence cyanide-bridged complex, Br3Fe（p-NC）RuBr（dppm）2 （dppm = bis（diphenylphosphino）methane）, was obtained through the reaction between trans-（dppm）2C1- RuCN and FeBr3. Its crystal structure was characterized. Electronic absorption spectra indicate the existence of metal-to-metal charge transfer （MMCT） and this complex is Class II mixed valence complexes according to the classification of Robin and Day. Magnetic analysis shows it is paramagnetic.展开更多
We have designed and synthesized a family of dinuclear cyanido-bridged complexes[PY5Me_(2)Ru(μ-CN)Ru(dppe)CpMe_(n)][PF_(6)]_(2) (PY5Me_(2)=2,6-bis (1,1-bis(2-pyridyl)ethyl) pyridine,Cp=cyclopentadienyl,n=0,2[PF6]_(2)...We have designed and synthesized a family of dinuclear cyanido-bridged complexes[PY5Me_(2)Ru(μ-CN)Ru(dppe)CpMe_(n)][PF_(6)]_(2) (PY5Me_(2)=2,6-bis (1,1-bis(2-pyridyl)ethyl) pyridine,Cp=cyclopentadienyl,n=0,2[PF6]_(2);n=1,3[PF6]_(2);n=5,4[PF6]_(2)) by using a mononuclear complex[PY5Me_(2)Ru(μ-CN)][PF_(6)](1) as the precursor.All the three complexes have been fully characterized by including single-crystal X-ray diffraction analysis.The one-electron oxidation complexes 2^(3+),3^(3+) and 4^(3+) obtained in situ all show a MMCT absorption band in the visible range.The MMCT energy increases as the redox potential of the N-terminal fragments decreases,and the redox potential decreases as the number of methyl groups on the cyclopentadiene of the cyanido-nitrogen coordinated Ru metal increases,supported by the TDF/TDDFT calculations.展开更多
To investigate how the electronic effect of ligand at donor site influences electronic communication or metal-to-metal charge transfer(MMCT)properties in similar mixed-valence(MV)complexes,a series of binuclear organo...To investigate how the electronic effect of ligand at donor site influences electronic communication or metal-to-metal charge transfer(MMCT)properties in similar mixed-valence(MV)complexes,a series of binuclear organometallic complexes,MeCp(dppe)RuCNFeCl_(3)(1),MeCp(PPh_(3))_(2)RuCNFeCl_(3)(2),Cp^(*)(dppe)FeCNFeCl_(3)(3),Cp^(*)(dppe)RuCNFeCl_(3)(4)and Cp^(*)(PPh_(3))_(2)RuCNFeCl_(3)(5),have been synthesized and characterized.The electronic absorptions of these complexes show the presence of MMCT properties between RuⅡ or FeⅡ and FeⅢ ions,strongly supported by the theoretical calculations.With increasing electron-donating ability of ligands(PPh3>dppe,Cp^(*)>MeCp)at donor site,the MMCT absorption bands are red-shifted,which expresses in the sequence of absorption bands with 1(500 nm),4(536 nm),2(542 nm),5(580 nm)from high-energy to low-energy.Meanwhile,the MMCT absorption energy of 4(536 nm)is larger than that of 3(760 nm)due to the stronger electron-donating ability of FeⅡ than RuⅡ.Furthermore,these complexes belong to the Class Ⅱ systems according to the Robin and Day’s classification.展开更多
The Middle Miocene Climate Transition(MMCT,~14 Ma)is the largest cooling event in the Cenozoic“Coolhouse”,which significantly impacts the global chemical weathering pattern.In this paper,the responses of the MMCT gl...The Middle Miocene Climate Transition(MMCT,~14 Ma)is the largest cooling event in the Cenozoic“Coolhouse”,which significantly impacts the global chemical weathering pattern.In this paper,the responses of the MMCT global cooling event in the deep South China Sea were studied by clay mineral assemblages analysis of the oceanic red beds(ORB)at International Ocean Discovery Program(IODP)Expedition 368 Site U1502.The results show that the clay mineral assemblages of the ORB at Site U1502 are mainly composed of smectite(56–88%),illite(7–29%),and kaolinite(6–20%),without chlorite.The contents of these clay minerals and illite crystallinity show a four-stage variation pattern during early-middle Miocene(22.8–10.8 Ma).Smectite decreased from average 81%during 22.8–16.2 Ma and 16.2–14.4 Ma to average 67%during 13.8–10.8 Ma,with a rapid decrease of~14%during 14.4–13.8 Ma.On the contrary,illite and kaolinite increased rapidly by~8%and~6%,respectively,during 14.4–13.8 Ma.Illite crystallinity increased from average 0.18°Δ2θduring 22.8–16.2 Ma to average 0.19°Δ2θduring 16.2–14.4 Ma,and then decreased rapidly by~0.02°Δ2θduring 14.4–13.8 Ma.The provenance analysis of clay minerals shows that illite and kaolinite mainly originated from South China landmass due to physical erosion,while smectite mainly came from the Luzon arc as the product of chemical weathering.Therefore,smectite/illite ratio and illite crystallinity are used as proxies of chemical weathering intensity in the early-middle Miocene.High values of the ratio and the crystallinity represent the enhanced chemical weathering,whereas low values indicate the weakened chemical weathering or the strengthened physical erosion process.The smectite/illite ratio and illite crystallinity both decreased rapidly during 14.4–13.8 Ma,indicating the chemical weathering in the surrounding area of the South China Sea weakened rapidly,which we believe is the result of the MMCT event forcing.In addition,their values increased slightly during 16.2–14.4 Ma,which is in response to the relatively enhanced chemical weathering during the Middle Miocene Climate Optimum(MMCO).The variation pattern of clay mineral assemblages of the early-middle Miocene ORB in the South China Sea and its rapid transformation during the MMCT reveal that the Cenozoic cooling played a specific role in controlling the chemical weathering of the Earth’s surface.展开更多
基金supported by the 973 Program(2012CB821702,2014CB845603)the National Natural Science Foundation of China(21233009,21203194 and 21173223)
文摘A new mixed-valence cyanide-bridged complex, Br3Fe（p-NC）RuBr（dppm）2 （dppm = bis（diphenylphosphino）methane）, was obtained through the reaction between trans-（dppm）2C1- RuCN and FeBr3. Its crystal structure was characterized. Electronic absorption spectra indicate the existence of metal-to-metal charge transfer （MMCT） and this complex is Class II mixed valence complexes according to the classification of Robin and Day. Magnetic analysis shows it is paramagnetic.
基金the National Science Foundation of China(21773243,21973095)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB20010200)for financial support。
文摘We have designed and synthesized a family of dinuclear cyanido-bridged complexes[PY5Me_(2)Ru(μ-CN)Ru(dppe)CpMe_(n)][PF_(6)]_(2) (PY5Me_(2)=2,6-bis (1,1-bis(2-pyridyl)ethyl) pyridine,Cp=cyclopentadienyl,n=0,2[PF6]_(2);n=1,3[PF6]_(2);n=5,4[PF6]_(2)) by using a mononuclear complex[PY5Me_(2)Ru(μ-CN)][PF_(6)](1) as the precursor.All the three complexes have been fully characterized by including single-crystal X-ray diffraction analysis.The one-electron oxidation complexes 2^(3+),3^(3+) and 4^(3+) obtained in situ all show a MMCT absorption band in the visible range.The MMCT energy increases as the redox potential of the N-terminal fragments decreases,and the redox potential decreases as the number of methyl groups on the cyclopentadiene of the cyanido-nitrogen coordinated Ru metal increases,supported by the TDF/TDDFT calculations.
基金the National Science Foundation of China(21773243,21973095)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB20010200)for financial support。
文摘To investigate how the electronic effect of ligand at donor site influences electronic communication or metal-to-metal charge transfer(MMCT)properties in similar mixed-valence(MV)complexes,a series of binuclear organometallic complexes,MeCp(dppe)RuCNFeCl_(3)(1),MeCp(PPh_(3))_(2)RuCNFeCl_(3)(2),Cp^(*)(dppe)FeCNFeCl_(3)(3),Cp^(*)(dppe)RuCNFeCl_(3)(4)and Cp^(*)(PPh_(3))_(2)RuCNFeCl_(3)(5),have been synthesized and characterized.The electronic absorptions of these complexes show the presence of MMCT properties between RuⅡ or FeⅡ and FeⅢ ions,strongly supported by the theoretical calculations.With increasing electron-donating ability of ligands(PPh3>dppe,Cp^(*)>MeCp)at donor site,the MMCT absorption bands are red-shifted,which expresses in the sequence of absorption bands with 1(500 nm),4(536 nm),2(542 nm),5(580 nm)from high-energy to low-energy.Meanwhile,the MMCT absorption energy of 4(536 nm)is larger than that of 3(760 nm)due to the stronger electron-donating ability of FeⅡ than RuⅡ.Furthermore,these complexes belong to the Class Ⅱ systems according to the Robin and Day’s classification.
基金supported by the National Key Research and Development Program of China (Grant No. 2018YFE0202402)the Shanghai Science and Technology Innovation Action Plan (Grant No. 20590780200)the National Natural Science Foundation of China (Grant Nos. 41530964 & 41942046)
文摘The Middle Miocene Climate Transition(MMCT,~14 Ma)is the largest cooling event in the Cenozoic“Coolhouse”,which significantly impacts the global chemical weathering pattern.In this paper,the responses of the MMCT global cooling event in the deep South China Sea were studied by clay mineral assemblages analysis of the oceanic red beds(ORB)at International Ocean Discovery Program(IODP)Expedition 368 Site U1502.The results show that the clay mineral assemblages of the ORB at Site U1502 are mainly composed of smectite(56–88%),illite(7–29%),and kaolinite(6–20%),without chlorite.The contents of these clay minerals and illite crystallinity show a four-stage variation pattern during early-middle Miocene(22.8–10.8 Ma).Smectite decreased from average 81%during 22.8–16.2 Ma and 16.2–14.4 Ma to average 67%during 13.8–10.8 Ma,with a rapid decrease of~14%during 14.4–13.8 Ma.On the contrary,illite and kaolinite increased rapidly by~8%and~6%,respectively,during 14.4–13.8 Ma.Illite crystallinity increased from average 0.18°Δ2θduring 22.8–16.2 Ma to average 0.19°Δ2θduring 16.2–14.4 Ma,and then decreased rapidly by~0.02°Δ2θduring 14.4–13.8 Ma.The provenance analysis of clay minerals shows that illite and kaolinite mainly originated from South China landmass due to physical erosion,while smectite mainly came from the Luzon arc as the product of chemical weathering.Therefore,smectite/illite ratio and illite crystallinity are used as proxies of chemical weathering intensity in the early-middle Miocene.High values of the ratio and the crystallinity represent the enhanced chemical weathering,whereas low values indicate the weakened chemical weathering or the strengthened physical erosion process.The smectite/illite ratio and illite crystallinity both decreased rapidly during 14.4–13.8 Ma,indicating the chemical weathering in the surrounding area of the South China Sea weakened rapidly,which we believe is the result of the MMCT event forcing.In addition,their values increased slightly during 16.2–14.4 Ma,which is in response to the relatively enhanced chemical weathering during the Middle Miocene Climate Optimum(MMCO).The variation pattern of clay mineral assemblages of the early-middle Miocene ORB in the South China Sea and its rapid transformation during the MMCT reveal that the Cenozoic cooling played a specific role in controlling the chemical weathering of the Earth’s surface.
