• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Two Zn(Ⅱ) and Cd(Ⅱ) Metal-Organic Frameworks with Mixed Ligands:Synthesis,Structure,Sorption and Luminescent Properties

    2020-06-21 10:03:02LIYuLingZHAOYueSUNWeiYin

    LI Yu-LingZHAO YueSUN Wei-Yin

    (1State Key Laboratory of Coordination Chemistry,School of Chemistry and Chemical Engineering,Nanjing University,Nanjing 210023,China)

    (2School of Chemical Engineering and Food Science,Zhengzhou University of Technology,Zhengzhou 450044,China)

    Abstract:Two new metal-organic frameworks(MOFs)[Cd3(tib)2(BPT)2(H2O)2]·DMA·6H2O(1)and[Zn2(tib)(HBTB)2(H2O)]·2H2O(2)(tib=1,3,5-tris(1-imidazolyl)benzene,H3BPT=biphenyl-3,4′,5-tricarboxylic acid,H3BTB=4,4′,4″-benzene-1,3,5-triyl-tribenzoic acid,DMA=N,N-dimethylacetamide)were synthesized and characterized.Complex 1 is a 4-nodal three-dimensional(3D)framework with point symbol{83}4{85·12}{86}2,while 2 is a two-dimensional(2D)network to be joined together by hydrogen bonds to generate a 3D supramolecular structure.Gas/vapor adsorption and luminescence behavior of the two complexes were studied.It is meaningful that 1 and 2 can selectively adsorb CO2 over N2,and MeOH over EtOH.Furthermore,1 can selectively detect acetone through a fluorescence quenching mechanism in the organic solvents including MeOH,EtOH,2-PA,CH3CN,DMF,DMA,THF,CHCl3,CH2Cl2 and acetone.CCDC:1996242,1;1845264,2.

    Keywords:Zn(Ⅱ) and Cd(Ⅱ) MOFs;sorption properties;luminescent properties

    Over the past years,the rational design and synthesis of functional metal-organic frameworks(MOFs)materials have caused remarkable attention due to their rich and varied structures as well as potential application,such as gas storage and separation,magnetism,heterogeneous catalysis,drug delivery and luminescence[1-8].However,it still remains challenging by control-synthesizing and predicting structures of the functional MOFs because of many factors which can affect the structures and properties of MOFs.Among these factors,the selection of organic linkers is very crucial for formation of MOFs with definite framework structures and desired properties.Therefore,proper organic bridging linkers are significant in building the desired MOFs materials.As for as we know,biphenyl-3,4′,5-tricarboxylic acid(H3BPT)and 4,4′,4″-benzene-1,3,5-triyl-tribenzoic acid (H3BTB)(Scheme 1)are good bridging ligands because of their diversified coordination modes and rigid multicarboxylic groups[9-12].

    Scheme 1 Coordination modes of BPT3-and HBTB2-in 1 and 2

    In our previous studies,a rigid tridentate ligand 1,3,5-tris(1-imidazolyl)benzene(tib)as a N-donor ligand have been used in construction of MOFs,and the results showed that it can react with varied metal salts leading to the formation of MOFs with specific structures and interesting properties[13-15].Thus,it is meaningful for using mixed N-donor ligand tib and multicarboxylic acids H3BPT/H3BTB to construct MOFs with novel structures and properties.In this work,two new metal-organic frameworks, [Cd3(tib)2(BPT)2(H2O)2]·DMA·6H2O(1)and[Zn2(tib)(HBTB)2(H2O)]·2H2O(2)(tib=1,3,5-tris(1-imidazolyl)benzene,H3BPT=biphenyl-3,4′,5-tricarboxylic acid,H3BTB=4,4′,4″-benzene-1,3,5-triyl-tribenzoic acid,DMA=N,N-dimethylacetamide),were synthesized and characterized.Structural characterization reveals that complex 1 is a 4-nodal 3D framework with point symbol{83}4{85·12}{86}2,while 2 is a 2D network to be joined togetherby hydrogen bonds to generate a 3D supramolecular structure.Gas/vapor adsorption and luminescence behavior of the two complexes were studied.It is meaningful that 1 and 2 can selectively adsorb CO2over N2,and MeOH over EtOH.Furthermore,1 can selectivity detect acetone through a fluorescence quenching mechanism in the organic solvents including MeOH,EtOH,2-PA,CH3CN,DMF,DMA,THF,CHCl3,CH2Cl2and acetone.

    1 Experimental

    1.1 Materials and measurements

    All commercially available chemicals and solvents are of reagent grade and were used as received without further purification.Ligand tib was prepared according to the procedures reported previously[16].Elemental analyses for C,H and N were performed on a FLASH EA 1112 elemental analyzer.Thermogravimetric analyses(TGA)were carried out on a Mettler-Toledo (TGA/DSC1)thermal analyzer under nitrogen with a heating rate of 10℃·min-1.FT-IR spectra were recorded in a range of 400~4 000 cm-1on a BRUKER TENSOR 27 spectrophotometer using KBr pellets.Powder X-ray diffraction (PXRD)analyses were performed on a Bruker D8 Advance X-ray diffractometer with Cu Kα (λ=0.154 18 nm)radiation,in which the X-ray tube was operated at 40 kV and 40 mA,and the scanning angle range was between 5°and 50°.Sorption experiments were carried out on a Belsorp-max volumetric gas sorption instrument.The lumine-scence spectra were recorded on an Aminco Bowman Series 2 spectrofluorometer with a xenon arc lamp as the light source.The pass width of 10 nm was used in the measurements of emission and excitation spectra,and all the measurements were performed under the same experimental conditions.

    1.2 Synthesis of[Cd3(tib)2(BPT)2(H2O)2]·DMA·4H2O(1)

    A mixture of tib (13.8 mg,0.05 mmol),H3BPT(14.3 mg,0.05 mmol),and Cd(NO3)2·4H2O(30.0 mg,0.1 mmol)in DMA/H2O (8 mL,3∶1,V/V)was placed in an 18 mL Teflon-lined stainless steel container and heated at 90 ℃ for 72 h.Thereafter,colorless blockshaped crystals of 1 were isolated in 80%yield(based on tib).Elemental analysis Calcd.for C64H63N13O21Cd3(%):C 45.55,H 3.76,N 10.79;Found(%):C 45.28,H 3.91,N 10.72.IR(KBr pellet,cm-1):3 357(m),3 143(m),1 670(m),1 610(m),1 569(s),1 403(s),1 357(m),1 278(m),1 191(m),1 096(m),1 051(m),932(m),852(m),792(s),674(m),558(m),447(m).

    1.3 Synthesis of[Zn2(tib)(HBTB)2(H2O)]·2H2O(2)

    Complex 2 was synthesized by tib(13.8 mg,0.05 mmol),H3BTB (22.0 mg,0.05 mmol)and Zn(NO3)2·6H2O(30.0 mg,0.1 mmol)in H2O(8 mL)in a 18 mL glass vial and heated at 160℃for 72 h.After cooling to room temperature,colorless block crystals of 2 were obtained with a yield of 75%based on tib.Anal.Calcd.for C69H50N6O15Zn2(%):C 62.13,H 3.78,N 6.30;Found(%):C 62.07,H 3.85,N 6.25.IR(KBr pellet,cm-1):3 449(m),1 689(s),1 662(s),1 620(s),1 511(m),1 401(s),1 240(m),1 177(m),1 075(s),1 015(s),946(m),854(m),774(s),683(m),646(m),482(m).

    1.4 Sample activation

    Solvent-exchanged samples were prepared by immersing the as-synthesized samples 1 in THF for 3 days to remove the nonvolatile solvates,the solvent was decanted every 8 h,and fresh THF was added.The activated sample 1′was obtained by heating the solvent-exchanged samples at 423 K under a dynamic high vacuum for 10 h.The activated samples 2′was obtained by heating the sample 2 directly at 423 K under a dynamic high vacuum for 10 h.

    1.5 X-ray crystallography

    Crystallographic data of 1 and 2 were collected on a Bruker Smart ApexⅡCCD area-detector diffractometer with graphite-monochromated Mo Kα radiation(λ =0.071 073 nm)using the ω-scan technique.The diffraction data were integrated using the SAINT program[17],which were also used for the intensity corrections for the Lorentz and polarization effects.Semi-empirical absorption correction was applied using the SADABS program[18].Complex 1 was solved by direct methods using SHELXT-2014 and all the non-hydrogen atoms were refined anisotropically on F2by the full-matrix least-squares technique with the SHELXL-2018[19-20].Complex 2 was solved by direct methods using SHELXT-2014 and all the nonhydrogen atoms were refined anisotropically on F2by the full-matrix least-squares technique with the SHELXL-2014[19].All the hydrogen atoms,except for those of water molecules,were generated geometrically and refined isotropically using the riding model.The hydrogen atoms of the coordinated water molecules were found from the Fourier map directly,while those of free water molecules were not found.Because some free solvent molecules in 1 are highly disordered and impossible to refine using conventional discrete-atom models,the SQUEEZE subroutine of the PLATON software suite[21-22]was applied to remove the scattering from the highly disordered solvent molecules.The formula of 1 was calculated based on volume/count_electron analysis,thermogravimetric analysis(TGA)and elemental analysis.The reported refinements are of the guest-free structures obtained by the SQUEEZE routine,and the results are attached to the CIF file.The details of the crystal parameters,data collection,and refinements for the 1 and 2 are listed in Table 1.Selected bond lengths and angles are given in Table S1,and the hydrogen bond data for 2 are provided in Table S2.

    CCDC:1996242,1;1845264,2.

    Table 1 Crystal data and structure refinements for 1 and 2

    Continued Table 1

    2 Results and discussion

    2.1 Crystal structure of[Cd3(tib)2(BPT)2(H2O)2]·DMA·6H2O(1)

    X-ray crystallographic analyses show that1 crystallizes in the C2/c space group (Table 1).As shown in Fig.1a,the asymmetric unit of 1 contains two crystallographically independent Cd(Ⅱ) cations,which have different coordination environments.The Cd1 is in a distorted tetrahedral coordination geometry with two N atoms(N1,N1A)from two different tib ligands and two carboxylate O atoms (O1,O1A)from two distinct BPT3-anions,while the Cd2 is six-coordinated with a distorted octahedral geometry by two imidazole N atoms (N6B,N4C)from two different tib ligands,three carboxylate O atoms(O3D,O4D,O5)from two different BPT3-anions,and one coordinated water molecule.The Cd-N and Cd-O bond lengths are found to be 0.227 7(3)~0.236 0(3)and 0.217 7(3)~0.248 0(3)nm,respectively(Table S1).Moreover,the coordination angles around Cd are in a range of 55.12(8)°~178.81(12)°(Table S1).In 1,each Cd(Ⅱ) ion connects two tib and every tib joins three Cd(Ⅱ)ions to form a 2D network (Fig.1b).Meanwhile,each BPT3-ligand adopts the coordination mode (κ1)-(κ1)-(κ2)-μ3-BPT coordination mode (Scheme 1,mode Ⅰ)to connect three Cd(Ⅱ) cations and every Cd(Ⅱ) links two ligands to build a 2D Cd-BPT structure(Fig.1c).The 2D Cdtib and 2D Cd-BPT are interspersed with Cd ions as nodes to generate the final 3D structure(Fig.1d).According to the simplification principle,Cd1,Cd2,tib,and BPT3-can be viewed as four-,four-,three-,and three-connectors,respectively.So,the resulting structure of 1 is a (3,3,4,4)-connected 4-nodal 3D framework with a{83}4{85·12}{86}2topology(Fig.1e)[23].Additionally,the solvent-accessible volume of 1 is 2.025 4 nm3per 7.338 4 nm3unit cell volume(27.6%of the total crystal volume)[24].

    2.2 Crystal structure of[Zn2(tib)(HBTB)2(H2O)]·2H2O(2)

    Fig.1 (a)Coordination environment around Cd(Ⅱ)in 1;(b)2D Cd-tib network in 1;(c)2D Cd-BPT network structure in 1;(d)3D packing structure of 1(Grey color:2D Cd-tib network,Green color:1D Cd-BPT chain structure);(e)Topological presentation of 1

    When the H3BPT was replaced by H3BTB,complex 2 was isolated.As illustrated in Fig.2a,the asymmetric unit of 2 contains two crystallographically independent Zn ions.Zn1 is six-coordinated with distorted octahedral geometry by two imidazole N atoms (N1,N5A)from two different tib and four carboxylate O ones(O1,O2,O7,O8)from two distinct HBTB2-,with Zn1-N bond distance from 0.201 9(3)to 0.202 3(4)nm and the Zn1-O one from 0.196 2(3)to 0.198 2(3)nm.Furthermore,the coordination angles around Zn1 are in the scope of 97.54(13)°~121.79(15)°(Table S1).While Zn2 is five-coordinated by one imidazole N atom (N3B)from tib ligand,three carboxylate O atoms(O3,O11C,O12C)from different HBTB2-and one terminal water molecule(O1W).The bond lengths and coordination angles around Zn2 are in normal range (Table S1).In 2,each Zn1 ions joins two tib molecules and each tib ligand connects two Zn1 ions to construct a 1D chain(Fig.2b).Meanwhile,partly deprotonated HBTB2-ligand adopts(κ1)-(κ2)-μ2-HBTB or(κ2)-(κ2)-μ2-HBTB coordination mode(Scheme 1,modeⅡ andⅢ)to connect two Zn(Ⅱ) ions to form a 1D chain structure (Fig.2c).The combination of 1D Zn-tib chain and 1D Zn-HBTB chain generate a final 2D network structure of 2 (Fig.2d).Eventually,hydrogen bonding C(10)-H(10A)…O1W and C(3)-H(3)…O11(Table S2)bridge the layers to form a 3D supramolecular structure of 2(Fig.2e).

    Fig.2 (a)Coordination environment of Zn(Ⅱ)in 2;(b)1D chain structure of Zn-tib in 2 along b axis;(c)1D chain structure of Zn-HBTB in 2 along c axis;(d)2D layer structure of 2;(e)3D supramolecular structure of 2 with hydrogen bonds indicated by dashed lines

    2.3 Powder X-ray diffraction(PXRD)and thermal stability

    The purity for the bulky samples of synthesized 1 and 2 were confirmed by PXRD tests and the results are provided in Fig.S1.Each PXRD pattern of the asprepared sample was well consistent with the simulated one,confirming the phase purity of the products.

    Thermogravimetric analysis (TGA)was carried out in evaluating the thermal stability of the frameworks and the TGA curves of 1 and 2 are shown in Fig.S2.Complex 1 showed a weight loss of 13.2%between 30 and 245℃corresponding to the removal of free and coordinated H2O molecules as well as free DMA molecules(Calcd.13.4%).Further weight loss was observed at about 350℃,implying collapse of the framework of complex 1(Fig.S2a).TGA curve of 2 gave weight loss of 4.4% from 30 to 185℃,originating from the loss oftwo free and one coordinated H2O molecules (Calcd.4.0%),and the framework is stable up to about 395℃(Fig.S2b).

    2.4 Gas and vapor adsorption properties

    The porosity and high stability of the frameworks prompted us to examine their gas/vapor sorption behavior.The sorption performances of the activated samples 1′and 2′for N2at 77 K,CO2at 195 K,MeOH and EtOH at 298 K are discussed here.

    From the Fig.3a,we can see the adsorption isotherm of N2at 77 K for 1′,which suggests only surface adsorption[25].However,as shown in Fig.3a and 3b,the adsorption capacities of CO2,MeOH,and EtOH on 1′are considerable.The CO2adsorption capacity of 1′at 195 K and 100 kPa was 81.12 cm3·g-1,corresponding to about 5.8 CO2molecules per formula unit,while the uptake amount of CH3OH and CH3CH2OH at 298 K and 100 kPa was 105.81 cm3·g-1(151.04 mg·g-1)and 33.32 cm3·g-1(68.54 mg·g-1),corresponding to 7.6 MeOH molecules and 2.4 EtOH molecules per formula unit,respectively.The observed hysteretic adsorption and incomplete desorption behavior suggest strong interactions between adsorbed CO2and the framework[26-29].Considering all of the above analysis results,it can be seen that complex 1 can selectively adsorb CO2and MeOH molecules.

    It is noteworthy that almost no adsorption of N2at 77 K and EtOH at 298 K was found for 2′(Fig.4a and 4b).The final value of CO2adsorption at 195 K and 100 kPa was 32.14 cm3·g-1corresponding to about 1.9 CO2molecules per formula unit for 2′.As for MeOH adsorption of 2′at 298 K (Fig.4b),the final value of 47.3 cm3·g-1(71.8 mg·g-1)at 100 kPa corresponds to 2.8 MeOH molecules per formula unit for 2′.The hysteresis and incomplete desorption suggest the strong interactions between the adsorbate and adsorbent,which include the hydrogen bond interactions between the guest molecules and framework,as well as the guest molecules and the guest molecules.

    Fig.3 (a)Sorption isotherms of N2 at 77 K and CO2 at 195 K for 1′;(b)Sorption isotherms of MeOH and EtOH at 298 K for 1′

    Fig.4 (a)N2 at 77 K and CO2 at 195 K sorption isotherms for 2′;(b)MeOH and EtOH at 298 K sorption isotherms for 2′

    2.5 Fluorescence sensing properties

    MOFs constructed from d10-metal ions and πconjugated skeleton ligands are usually considered to be potential luminescent materials[30-34].Accordingly,the luminescence properties of tib,H3BPT ligands and 1 were studied in the solid state at room temperature.It was found that 1 displayed apparent fluorescence enhancement and the intense emission bands were observed at λem=398 nm (λex=335 nm)as exhibited in Fig.5,which may be attributed to the tib and H3BPT ligands emission since the free tib and H3BPT ligands exhibited emission at 402 and 408 nm (λex=295 nm),respectively[35-36].It has been reported that the construction of architectures can enhance the rigidity ofthe aromatic backbone ofthe ligands and strengthen the intramolecular/intermolecular interactions among the organic ligands,which are beneficial to energy transfer[37].Compared with the free tib and H3BPT ligands,the observed much stronger emission intensity of 1 implies that the formation of MOFs enhances the fluorescence of the ligand.

    Fig.5 Solid-state photoluminescence spectra of the free tib and H3BPT ligands(λex=295 nm)and 1(λex=335 nm)at room temperature

    To examine the potential sensing properties for small organic solvent molecules,the fluorescence experiments of 1 were carried out by dispersing 5 mg well-ground crystalline powder samples in 3 mL different organic solvents including MeOH,EtOH,2-propanol(2-PA),CH3CN,DMF,DMA,THF,CHCl3,CH2Cl2and acetone.As illustrated in Fig.6,the intensity of the photoluminescent(PL)of 1 distinctly depended on the identity of the solvent molecule and the emission intensity of 1 in MeOH dispersion was stronger than those in other solvent dispersions under the same concentration.Therefore,MeOH was chose as dispersion solvent in the sensing studies.Furthermore,only addition of acetone can quench the fluorescence emissions of 1 efficiently.These experimental phenomena can be mainly attributed to dierent interactions between the framework architecture and distinct organics[38].

    Fig.6 Photoluminescence intensities of 1 introduced into different pure organic solvents when excited at 335 nm

    To examine the sensing sensitivity of 1 toward acetone in detail,a batch of suspensions of 1 were dispersed in MeOH solution,respectively,with gradually increasing acetone concentration.As exhibited in Fig.7,with the addition of acetone into the suspensions of 1,a gradual decrease of the fluorescence intensity was observed.The results of fluorescence titration of 1 show that about 50%decrease of the luminescence intensity was reached with the addition of 5 μL acetone,and the luminescence was almost completely quenched with the addition of 50 μL acetone.Therefore the tib-composed complex 1 may be served as a potential fluorescent sensing material.

    Fig.7 Fluorescence titrations of compound 1 dispersed in 1 mg·mL-1MeOH with gradual addition of acetone

    3 Conclusions

    In summary,two new Cd(Ⅱ) and Zn(Ⅱ)-based MOFs with mixed tib and tricarboxylate ligands have been synthesized.Gas/vapor adsorption and luminescence behavior of the complexes were investigated and the results indicate that complexes 1 and 2 both show the ability to selectively adsorb CO2over N2,MeOH over EtOH,suggesting a possible application in selective gas/vapor adsorption and separation.More importantly,complex 1 shows unique selectivity for detection of acetone through luminescence quenching mechanism.It can be seen that the mixed ligand is an effective strategy for assembling MOF-based functional material.

    Acknowledgements:We gratefully acknowledge the Key Projects of Henan Provincial High School (GrantNo.18A150042)for financial support of this work.This work was also financially supported by the National Research Project Incubation Fund of Zhengzhou University of Technology(Grant No.GJJKTPY2018K1).

    Supporting information is available at http://www.wjhxxb.cn

    久久久久国产精品人妻一区二区| 久久精品国产a三级三级三级| 秋霞伦理黄片| 日韩一本色道免费dvd| 亚洲国产精品专区欧美| 天天躁日日操中文字幕| 久热久热在线精品观看| 高清视频免费观看一区二区| 精品人妻视频免费看| 噜噜噜噜噜久久久久久91| 成年人午夜在线观看视频| 久热久热在线精品观看| 三级经典国产精品| 精华霜和精华液先用哪个| 狂野欧美激情性xxxx在线观看| 国产片特级美女逼逼视频| 最近最新中文字幕大全电影3| 国产中年淑女户外野战色| 久久久久久久久久久丰满| 国产毛片在线视频| 亚洲av中文av极速乱| 大码成人一级视频| 简卡轻食公司| 精品久久久久久久人妻蜜臀av| 国产男女超爽视频在线观看| 最近最新中文字幕免费大全7| 国产精品久久久久久av不卡| 高清在线视频一区二区三区| 国产熟女欧美一区二区| 丰满人妻一区二区三区视频av| 大片免费播放器 马上看| 欧美成人精品欧美一级黄| 亚洲,欧美,日韩| 国产精品国产三级专区第一集| 精品久久久久久久久av| 免费黄色在线免费观看| 欧美日本视频| 免费看a级黄色片| 国产亚洲最大av| av女优亚洲男人天堂| 久久久久久久亚洲中文字幕| 边亲边吃奶的免费视频| 综合色av麻豆| 99热全是精品| 欧美人与善性xxx| 国产精品福利在线免费观看| av国产精品久久久久影院| 欧美丝袜亚洲另类| 伦精品一区二区三区| 国产精品偷伦视频观看了| 我要看日韩黄色一级片| 又爽又黄无遮挡网站| 91精品一卡2卡3卡4卡| 91午夜精品亚洲一区二区三区| 一边亲一边摸免费视频| 精品人妻熟女av久视频| 亚洲欧美成人精品一区二区| 少妇人妻一区二区三区视频| 毛片一级片免费看久久久久| 国产久久久一区二区三区| 黄色一级大片看看| 久久久久久伊人网av| 精品久久久久久久末码| 国产一区有黄有色的免费视频| 欧美日韩一区二区视频在线观看视频在线 | 最近手机中文字幕大全| 中文字幕人妻熟人妻熟丝袜美| 国产男女超爽视频在线观看| 久久久国产一区二区| 亚洲精品日本国产第一区| 久久久久久久亚洲中文字幕| 制服丝袜香蕉在线| 男女国产视频网站| 免费看日本二区| 十八禁网站网址无遮挡 | 久久久精品免费免费高清| 一级毛片黄色毛片免费观看视频| 日韩三级伦理在线观看| 国产美女午夜福利| 久久久久久久久久成人| 一区二区av电影网| 一本久久精品| 免费少妇av软件| 身体一侧抽搐| 嫩草影院精品99| 啦啦啦啦在线视频资源| 亚洲经典国产精华液单| 国产精品人妻久久久影院| 老司机影院成人| 联通29元200g的流量卡| 欧美亚洲 丝袜 人妻 在线| 18禁在线播放成人免费| 18禁动态无遮挡网站| 国产精品不卡视频一区二区| 国产黄频视频在线观看| 亚洲精品影视一区二区三区av| 亚洲国产日韩一区二区| 菩萨蛮人人尽说江南好唐韦庄| 国产免费一区二区三区四区乱码| 中文字幕久久专区| 中文天堂在线官网| 国产综合精华液| 蜜桃亚洲精品一区二区三区| 插逼视频在线观看| 2018国产大陆天天弄谢| 国产精品伦人一区二区| 美女脱内裤让男人舔精品视频| 91aial.com中文字幕在线观看| 精品少妇久久久久久888优播| 国产精品蜜桃在线观看| 网址你懂的国产日韩在线| www.色视频.com| 日本一二三区视频观看| 日韩一区二区视频免费看| 亚洲av中文av极速乱| 视频中文字幕在线观看| 中文字幕人妻熟人妻熟丝袜美| 亚洲欧美一区二区三区黑人 | 精品一区二区免费观看| 乱系列少妇在线播放| 中文资源天堂在线| 99久久精品热视频| 国产成人aa在线观看| 97超碰精品成人国产| 中文欧美无线码| 国产亚洲午夜精品一区二区久久 | 亚洲欧美成人综合另类久久久| 丰满少妇做爰视频| 赤兔流量卡办理| 自拍偷自拍亚洲精品老妇| 亚洲,一卡二卡三卡| 久久精品国产鲁丝片午夜精品| 全区人妻精品视频| 视频区图区小说| 91在线精品国自产拍蜜月| av又黄又爽大尺度在线免费看| 亚洲一区二区三区欧美精品 | 亚洲国产精品成人综合色| 99久久精品国产国产毛片| 尤物成人国产欧美一区二区三区| 国产高清不卡午夜福利| 少妇人妻 视频| 午夜免费观看性视频| 中文资源天堂在线| 国产真实伦视频高清在线观看| 成人漫画全彩无遮挡| 日韩一区二区三区影片| 久久久久久久国产电影| 亚洲av二区三区四区| 日韩不卡一区二区三区视频在线| 一级毛片久久久久久久久女| 观看美女的网站| 国产精品一区www在线观看| 麻豆乱淫一区二区| 乱码一卡2卡4卡精品| 欧美最新免费一区二区三区| 精华霜和精华液先用哪个| 综合色av麻豆| 久久久久九九精品影院| 国产精品一二三区在线看| 联通29元200g的流量卡| 在线天堂最新版资源| 欧美日韩视频精品一区| 成人特级av手机在线观看| 日本一二三区视频观看| 国产爽快片一区二区三区| 欧美人与善性xxx| 国产亚洲5aaaaa淫片| 夫妻午夜视频| 亚洲精品日本国产第一区| 99热这里只有是精品50| 三级男女做爰猛烈吃奶摸视频| 欧美日韩在线观看h| 精品午夜福利在线看| 欧美xxxx黑人xx丫x性爽| 美女高潮的动态| 午夜免费观看性视频| 国产精品一区二区性色av| 国产欧美另类精品又又久久亚洲欧美| 午夜福利视频精品| 看黄色毛片网站| 少妇丰满av| 亚洲最大成人手机在线| 麻豆成人av视频| 免费电影在线观看免费观看| 在线免费观看不下载黄p国产| 久久鲁丝午夜福利片| 爱豆传媒免费全集在线观看| 在线亚洲精品国产二区图片欧美 | 国产精品国产三级国产专区5o| 少妇高潮的动态图| 国产视频首页在线观看| tube8黄色片| 男女边摸边吃奶| 国精品久久久久久国模美| 真实男女啪啪啪动态图| 又大又黄又爽视频免费| 久久久久性生活片| 人妻夜夜爽99麻豆av| 久久99热这里只频精品6学生| 国产日韩欧美亚洲二区| 只有这里有精品99| 亚洲国产色片| 国产男女超爽视频在线观看| 黄色怎么调成土黄色| 国产综合懂色| 男人舔奶头视频| 美女内射精品一级片tv| 国产伦在线观看视频一区| 久久久久久久久大av| 在线免费观看不下载黄p国产| 久久女婷五月综合色啪小说 | 国产日韩欧美在线精品| 在线观看一区二区三区| 最近的中文字幕免费完整| 国产黄片美女视频| 少妇裸体淫交视频免费看高清| 真实男女啪啪啪动态图| 亚洲欧美成人综合另类久久久| 51国产日韩欧美| 亚洲经典国产精华液单| 日韩成人av中文字幕在线观看| 丝袜喷水一区| 日本午夜av视频| 简卡轻食公司| 免费观看在线日韩| 国产成人a∨麻豆精品| 亚洲人成网站在线观看播放| 九色成人免费人妻av| 一区二区三区乱码不卡18| a级一级毛片免费在线观看| 97人妻精品一区二区三区麻豆| 欧美成人a在线观看| 在线亚洲精品国产二区图片欧美 | 综合色av麻豆| 国产探花在线观看一区二区| www.色视频.com| 韩国高清视频一区二区三区| 中文天堂在线官网| 免费观看的影片在线观看| 搞女人的毛片| 爱豆传媒免费全集在线观看| 国产在线一区二区三区精| freevideosex欧美| 国产老妇伦熟女老妇高清| 97超碰精品成人国产| 一本色道久久久久久精品综合| 欧美3d第一页| 日韩av在线免费看完整版不卡| 能在线免费看毛片的网站| 高清视频免费观看一区二区| 亚洲av福利一区| 午夜精品国产一区二区电影 | 毛片女人毛片| h日本视频在线播放| 久久久精品94久久精品| 日韩电影二区| xxx大片免费视频| 精品99又大又爽又粗少妇毛片| 22中文网久久字幕| 丰满少妇做爰视频| 网址你懂的国产日韩在线| 搡老乐熟女国产| 国产一区有黄有色的免费视频| 精品久久久久久久久亚洲| 黄色视频在线播放观看不卡| 欧美三级亚洲精品| 久久99热这里只频精品6学生| a级一级毛片免费在线观看| 我的女老师完整版在线观看| 熟妇人妻不卡中文字幕| 午夜福利在线在线| 久久久久国产精品人妻一区二区| 欧美精品一区二区大全| 18禁在线无遮挡免费观看视频| 熟女av电影| 亚洲自偷自拍三级| 观看免费一级毛片| 国产精品秋霞免费鲁丝片| 99热全是精品| 午夜日本视频在线| 亚洲国产精品成人久久小说| 亚洲电影在线观看av| 精品少妇久久久久久888优播| 午夜免费观看性视频| 国产精品国产三级国产av玫瑰| 免费看日本二区| 亚洲精品自拍成人| 国产精品嫩草影院av在线观看| 一个人看的www免费观看视频| av在线天堂中文字幕| 精品酒店卫生间| www.色视频.com| 国产精品久久久久久久久免| 国产午夜精品久久久久久一区二区三区| 下体分泌物呈黄色| 寂寞人妻少妇视频99o| 少妇猛男粗大的猛烈进出视频 | 少妇的逼好多水| 在线观看人妻少妇| www.色视频.com| 成人亚洲精品av一区二区| 2022亚洲国产成人精品| 韩国av在线不卡| 亚洲av欧美aⅴ国产| 丰满少妇做爰视频| 美女脱内裤让男人舔精品视频| 亚洲aⅴ乱码一区二区在线播放| 赤兔流量卡办理| 亚洲自偷自拍三级| 免费少妇av软件| 亚洲av.av天堂| 亚洲国产成人一精品久久久| 日本午夜av视频| 成年免费大片在线观看| 国产极品天堂在线| 国产中年淑女户外野战色| 亚洲精品aⅴ在线观看| 一级毛片我不卡| www.av在线官网国产| 成人漫画全彩无遮挡| 波多野结衣巨乳人妻| 国产成人精品婷婷| 国产日韩欧美在线精品| 自拍欧美九色日韩亚洲蝌蚪91 | 嘟嘟电影网在线观看| 亚洲精品,欧美精品| 免费黄色在线免费观看| 午夜福利高清视频| 国产 精品1| 国产午夜福利久久久久久| 嫩草影院入口| 成年版毛片免费区| 在线观看免费高清a一片| 久久久久国产网址| 亚洲,一卡二卡三卡| 搞女人的毛片| 视频中文字幕在线观看| 国产一区二区三区综合在线观看 | 麻豆乱淫一区二区| 欧美xxⅹ黑人| 91在线精品国自产拍蜜月| 久久亚洲国产成人精品v| 夫妻午夜视频| 亚洲欧美成人精品一区二区| 久久人人爽av亚洲精品天堂 | 国产一区二区三区av在线| 建设人人有责人人尽责人人享有的 | 久久久久国产网址| 在线观看免费高清a一片| 色综合色国产| 久久午夜福利片| 成年版毛片免费区| 亚洲国产最新在线播放| 国产高清不卡午夜福利| 日本一二三区视频观看| 人妻夜夜爽99麻豆av| 亚洲精品日本国产第一区| 国产一区二区三区av在线| 国产片特级美女逼逼视频| 国产av码专区亚洲av| 一级毛片我不卡| 精品国产露脸久久av麻豆| 最后的刺客免费高清国语| 99精国产麻豆久久婷婷| 亚洲综合精品二区| 欧美xxⅹ黑人| 国产精品久久久久久精品电影小说 | 亚洲精品乱码久久久久久按摩| av女优亚洲男人天堂| 亚洲精品aⅴ在线观看| 亚洲国产色片| 久久久午夜欧美精品| 少妇人妻精品综合一区二区| 亚洲激情五月婷婷啪啪| 欧美丝袜亚洲另类| 亚洲天堂av无毛| 天堂俺去俺来也www色官网| 日产精品乱码卡一卡2卡三| 国产中年淑女户外野战色| freevideosex欧美| 亚洲精品中文字幕在线视频 | 黄色一级大片看看| 欧美xxxx黑人xx丫x性爽| 日本熟妇午夜| 国产成人a∨麻豆精品| 亚洲经典国产精华液单| 禁无遮挡网站| 欧美精品人与动牲交sv欧美| a级毛色黄片| 日韩欧美精品v在线| 女人被狂操c到高潮| 五月伊人婷婷丁香| 又爽又黄a免费视频| 亚洲一级一片aⅴ在线观看| 国产 一区 欧美 日韩| 精品久久久久久电影网| 真实男女啪啪啪动态图| 精品久久国产蜜桃| 91狼人影院| 嫩草影院精品99| 欧美+日韩+精品| 91在线精品国自产拍蜜月| 99久久九九国产精品国产免费| 日日摸夜夜添夜夜爱| 黄色日韩在线| 国产亚洲av嫩草精品影院| 欧美激情国产日韩精品一区| 国产成人a∨麻豆精品| 99精国产麻豆久久婷婷| av女优亚洲男人天堂| 男人舔奶头视频| 欧美3d第一页| 亚洲国产av新网站| 日本一本二区三区精品| 丰满乱子伦码专区| 不卡视频在线观看欧美| 天天躁日日操中文字幕| 大话2 男鬼变身卡| 少妇人妻精品综合一区二区| 日本午夜av视频| 日本三级黄在线观看| 最近最新中文字幕免费大全7| 国产色婷婷99| 99九九线精品视频在线观看视频| 伦理电影大哥的女人| 日韩欧美精品免费久久| 麻豆久久精品国产亚洲av| 日韩 亚洲 欧美在线| 午夜福利在线在线| 午夜精品国产一区二区电影 | 午夜精品国产一区二区电影 | 国产欧美日韩一区二区三区在线 | 另类亚洲欧美激情| 国产高清有码在线观看视频| 九九在线视频观看精品| 国产精品一区www在线观看| 亚洲真实伦在线观看| 久久久久久久大尺度免费视频| 男女下面进入的视频免费午夜| 久久精品国产鲁丝片午夜精品| 亚洲自偷自拍三级| 国产精品不卡视频一区二区| 女人十人毛片免费观看3o分钟| 大陆偷拍与自拍| 麻豆成人午夜福利视频| 国产精品国产三级专区第一集| 特大巨黑吊av在线直播| 一本色道久久久久久精品综合| 午夜免费观看性视频| 一级毛片久久久久久久久女| 老司机影院毛片| 国产片特级美女逼逼视频| 日韩不卡一区二区三区视频在线| 热re99久久精品国产66热6| 免费看a级黄色片| 在线亚洲精品国产二区图片欧美 | 又爽又黄无遮挡网站| 在线观看一区二区三区| 高清毛片免费看| 色吧在线观看| 免费av观看视频| 免费观看无遮挡的男女| 制服丝袜香蕉在线| 国产69精品久久久久777片| 26uuu在线亚洲综合色| 国产日韩欧美亚洲二区| 成人特级av手机在线观看| 国产一区二区三区综合在线观看 | 欧美97在线视频| 国产亚洲最大av| 岛国毛片在线播放| 色婷婷久久久亚洲欧美| 国产午夜精品久久久久久一区二区三区| 高清毛片免费看| 一级片'在线观看视频| 人妻一区二区av| 午夜福利视频精品| 日韩欧美 国产精品| 精品一区二区三区视频在线| 久久99蜜桃精品久久| 久久精品国产亚洲av天美| 2018国产大陆天天弄谢| 日本熟妇午夜| 男人和女人高潮做爰伦理| 国产精品国产三级专区第一集| 熟妇人妻不卡中文字幕| 精品久久久久久久久av| 久久久久国产网址| 好男人在线观看高清免费视频| 午夜福利在线在线| 精品亚洲乱码少妇综合久久| 夫妻午夜视频| 女人久久www免费人成看片| 久久国内精品自在自线图片| freevideosex欧美| 高清在线视频一区二区三区| 综合色av麻豆| 老司机影院毛片| 国产黄色视频一区二区在线观看| 精华霜和精华液先用哪个| 国产一区有黄有色的免费视频| 在线观看国产h片| 人妻制服诱惑在线中文字幕| 老司机影院成人| 国产 一区精品| 观看免费一级毛片| 一级毛片久久久久久久久女| 欧美日韩一区二区视频在线观看视频在线 | 精品视频人人做人人爽| 啦啦啦中文免费视频观看日本| 在线天堂最新版资源| 国产乱来视频区| 菩萨蛮人人尽说江南好唐韦庄| 日韩欧美一区视频在线观看 | 美女xxoo啪啪120秒动态图| 在线a可以看的网站| 下体分泌物呈黄色| 最新中文字幕久久久久| 午夜免费观看性视频| 国产成人免费无遮挡视频| 五月开心婷婷网| 中文乱码字字幕精品一区二区三区| 国产精品成人在线| 又黄又爽又刺激的免费视频.| 深爱激情五月婷婷| 日本免费在线观看一区| 国产精品一二三区在线看| 我的女老师完整版在线观看| 91狼人影院| 美女cb高潮喷水在线观看| av在线观看视频网站免费| 高清在线视频一区二区三区| 中国国产av一级| 麻豆成人av视频| 久久国内精品自在自线图片| 日本色播在线视频| 亚洲在线观看片| 免费大片18禁| 寂寞人妻少妇视频99o| 国产精品久久久久久久久免| 2018国产大陆天天弄谢| 国产精品.久久久| 国产人妻一区二区三区在| 3wmmmm亚洲av在线观看| 国产伦精品一区二区三区四那| 亚洲,一卡二卡三卡| 欧美精品人与动牲交sv欧美| 亚洲不卡免费看| 久久精品综合一区二区三区| h日本视频在线播放| 一级黄片播放器| www.色视频.com| 日日摸夜夜添夜夜添av毛片| 插阴视频在线观看视频| 国产精品无大码| 夜夜爽夜夜爽视频| 一二三四中文在线观看免费高清| 久久精品人妻少妇| 久久精品国产a三级三级三级| 噜噜噜噜噜久久久久久91| 国产有黄有色有爽视频| 国产一级毛片在线| 有码 亚洲区| 人人妻人人澡人人爽人人夜夜| 51国产日韩欧美| 高清日韩中文字幕在线| 亚洲在久久综合| 亚洲欧美中文字幕日韩二区| 最新中文字幕久久久久| 欧美高清成人免费视频www| 能在线免费看毛片的网站| 亚洲欧美精品专区久久| 真实男女啪啪啪动态图| 国产高清有码在线观看视频| 日韩一本色道免费dvd| 极品少妇高潮喷水抽搐| 青青草视频在线视频观看| 天堂中文最新版在线下载 | 自拍偷自拍亚洲精品老妇| 99热这里只有是精品50| 国产成人免费无遮挡视频| 国产黄色免费在线视频| 99热这里只有是精品50| 一二三四中文在线观看免费高清| 亚洲av国产av综合av卡| 国产 一区 欧美 日韩| 91在线精品国自产拍蜜月| 日韩av不卡免费在线播放| 尤物成人国产欧美一区二区三区| 在线观看美女被高潮喷水网站| 天堂中文最新版在线下载 | 欧美日韩在线观看h| 成年女人在线观看亚洲视频 | 精品人妻偷拍中文字幕| 又爽又黄a免费视频| 日本av手机在线免费观看| 国产女主播在线喷水免费视频网站| 亚洲图色成人| 欧美性感艳星| 成人毛片a级毛片在线播放| 亚洲美女搞黄在线观看| 欧美一区二区亚洲| 久久久久久九九精品二区国产| 国产日韩欧美亚洲二区| 久久97久久精品| 亚洲精品自拍成人| 在线观看一区二区三区激情| 舔av片在线| 边亲边吃奶的免费视频| 亚洲天堂国产精品一区在线| 一区二区三区四区激情视频| 日韩av不卡免费在线播放| 国产精品麻豆人妻色哟哟久久| 一二三四中文在线观看免费高清|