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1.
The temperature‐dependent spreading performance of defined trisiloxane surfactants of the general formula [(CH3)3SiO]2CH3Si‐­(CH2)3(OCH2CH2)3–9OCH3 and Silwet L77 on a trimethylsilylated silicon‐wafer surface has been investigated. At 6 °C the tetraethylene glycol derivative showed the highest initial spreading rate. At 40 °C the octaethylene glycol derivative was the fastest spreader. It is shown that spreading behaviour and phase behaviour are closely related. The highest initial spreading rates were found for solutions in the two‐phase state (2Φ) closely above the liquid–liquid insolubility boundary. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

2.
The spreading behaviour of defined trisiloxane surfactants of general formula [(CH3)3SiO]2 CH3Si(CH2)3(OCH2CH2) nOCH3 (n = 3–9) on five different solid surfaces has been investigated. Maximum spreading areas and rates are found on non‐polar or slightly polar surfaces of 30 to 40 mN m−1 surface energy. Extremely low or high surface energies substantially reduce the spreading rates. On non‐polar surfaces rapid spreading is observed for 1 wt % solutions of the relatively short‐chained penta‐ and hexa‐ethylene glycol derivatives. On slightly polar surfaces dilute 0.1 wt % solutions of longer‐chained derivatives spread faster. This spreading pattern shift coincides with a change of the phase behaviour. Solutions of Silwet L77 do not prefer one specific surface, since 1 wt % solutions abruptly stop spreading after a few seconds and the maximum spreading rates are found for 0.1 wt % solutions. Therefore, Silwet L77 essentially belongs among the long‐chained derivatives. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

3.
The spreading behaviour of defined trimethylsilane‐based surfactants of general formula (CH3)3Si(CH2)6(OCH2CH2) nOCH3, n = 2–6, on five different solid surfaces at 21 °C has been investigated. Compounds bearing short diethylene and triethylene glycol hydrophiles do not spread. For the longer‐chained tetraethylene to hexaethylene glycol derivatives, the ability to spread depends on the surface energy. Rapid spreading is restricted to the slightly polar surface of 40 mN m−1 surface energy. Lower or higher surface energies considerably reduce the spreading rates. The phase behaviour of the solutions substantially influences the spreading process. The dispersed systems of the tetraethylene glycol derivative spread constantly over long time intervals. The dispersions of the pentaethylene glycol analogue are very close to the temperature for a transition into the one‐phase state. A retardation of the spreading process occurs after a few seconds. Micellar solutions of the hexaethylene glycol derivative either spread very slowly or stop spreading after a few seconds. The largest spreading areas and highest initial spreading rates were found for the 0.1 wt% solutions. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

4.
The spreading behaviour of binary and ternary equimolar mixtures of siloxane surfactants of general formula [(CH3)3SiO]2CH3Si(CH2)3 (OCH2CH2) nOCH3, n = 3–9, has been investigated. The mixtures show a pronounced temperature dependence on the initial spreading rate. Mixtures imitating the average oligoethylene glycol chain length n = 5 are the fastest spreaders at 15 °C. At 23 °C and 40 °C these mixtures spread fastest sucking n = 6 and n = 8, respectively. For a given average chain length an increasing length difference between the components of the binary mixtures reduces the initial spreading rate. Nevertheless, substantial differences between the phase transition temperature Tc from the lamellar phase (Lα) into the two‐phase state (2Φ) and the actual spreading temperature are tolerated. A clear relation between phase transition temperature Tc and initial spreading rate does not exist. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

5.
The organosilicone surfactant Silwet L‐77® (L‐77), used as an agrochemical adjuvant, is a mixture comprised predominantly of [(CH3)3SiO]2? (CH3)Si? (CH2)3? (OCH2CH2)n? OCH3 oligomers (n = 3–16, average n ≈ 7.5). The commercially available L‐77 mixture was purified by reversed‐phase high‐performance liquid chromatography (HPLC) to obtain individual trisiloxane surfactant components. Pure oligomers (n = 3, 6 and 9) were also synthesized. Synthesis was achieved by hydrosilylation of monomeric ethoxylate monomethyl ether starting reagents. Pure hexa‐ and nona‐ethylene glycols were produced by condensation of smaller oligomers. Atmospheric‐pressure ionization mass spectrometry (MS) methods were used to characterize fully the commercial L‐77 product and synthesized or isolated components. The application of Fourier‐transform ion cyclotron resonance MS and online HPLC–electrospray ionization MS techniques to the analysis of this surfactant are described here. The application of these analytical techniques also enabled elucidation of the synthetic by‐products present in the commercial formulation. In addition, physico‐chemical properties specific to agrochemical uses, such as droplet spread areas on plant foliage and surface tension for the different oligomer solutions, are also reported. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

6.
The dilational viscoelastic properties of Silwet L-77, a trisiloxane surfactant of the general formula (Me3SiO)2SiMe(CH2)3(OCH2CH2)7.5OH, at the air/water interface were investigated. Aqueous solutions of Silwet L-77 were spread onto a pendant drop and the dynamic surface tensions were measured by means of axisymmetric drop shape analysis. The surface dilatational elasticity, viscosity, and phase angle of the adsorption monolayer were also determined using the oscillating drop technique. The influences of frequency and concentration on the surface dilational properties were expounded. It is shown that the surface dilational modulus and elastic modulus increased with the increase of frequency, the viscous modulus was complex, while the phase angle decreased with the increase of frequency. Surface dilational modulus, elastic modulus, and viscous modulus passed through the maximum with the increase of bulk concentration and the phase angle increased with the increase of concentration.  相似文献   

7.
Reaction of Ti(OCH2CH2OR)4 (R?CH3 and C2H5) with 8‐hydroxyquinoline in benzene at room temperature resulted in the formation of Ti(C9H6NO)2(OCH2CH2OR)2, characterized by IR, 1H‐NMR, UV and mass spectroscopies. The molecular structure of Ti(C9H6NO)2(OCH2CH2OCH3)2 has been determined by single‐crystal X‐ray structure analysis. The geometry at titanium is a distorted octahedron, with the nitrogen atoms of quinolinate occupying the trans position with respect to oxygens of the 2‐methoxyethoxy groups. The prepared quinolinate derivatives of titanium alkoxides are very stable towards hydrolysis and harsh conditions are required for hydrolytic cleavage. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

8.
The gas-phase reaction products of the OH radical with 2-ethoxyethyl acetate (EEA, CH3C(O)OCH2CH2OCH2CH3) have been investigated. 1,2-Ethanediol acetate formate (EAF, CH3C(O)OCH2CH2OC(O)H) and ethyl formate (EF, HC(O)OCH2CH3) were identified as the two main products. A third product, ethylene glycol diacetate (EGD, CH3C(O)OCH2CH2OC(O)CH3), was also observed. EAF, EF, and EGD formation yields were determined to be 0.37 ± 0.03 and 0.328 ± 0.018 and 0.040 ± 0.005, respectively. Proposed reaction mechanisms are discussed and compared with these data. © 1996 John Wiley & Sons, Inc.  相似文献   

9.
新型三硅氧烷表面活性剂的合成与界面性能   总被引:10,自引:0,他引:10  
张国栋  韩富  张高勇 《化学学报》2006,64(11):1205-1208
低聚乙二醇单甲醚和环氧氯丙烷在相转移催化剂(P.T.C)存在下合成出低聚乙二醇甲醚缩水甘油醚, 然后与氨丙基三硅氧烷进行开环反应, 合成出了新型的三硅氧烷表面活性剂Me3SiOSiMeROSiMe3 [R=(CH2)3N(CH2CH(OH)CH2- (OCH2CH2)xOCH3)2, x=1, 2]. 通过1H NMR确证了这些目标产物的结构, 并且通过测定其水溶液的平衡表面张力研究了其表面活性. 在浓度约为10-4 mol•L-1时可以将水的表面张力降低至约21~22 mN•m-1.  相似文献   

10.
Neutral binuclear ruthenium complexes 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 of the general formula [{RuCl26p‐cym)}2 μ‐(NN)] (NN = bis(nicotinate)‐ and bis(isonicotinate)‐polyethylene glycol esters: (3‐py)COO(CH2CH2O)nCO(3‐py) and (4‐py)COO(CH2CH2O)nCO(4‐py), n =1–4), as well as mononuclear [RuCl26p‐cym)((3‐py)COO(CH2CH2OCH3)‐κN)], complex 9 , were synthesized and characterized using elemental analysis and electrospray ionization high‐resolution mass spectrometry, infrared, 1H NMR and 13C NMR spectroscopies. Stability of the binuclear complexes in the presence of dimethylsulfoxide was studied. Furthermore, formation of a cationic complex containing bridging pyridine‐based bidentate ligand was monitored using 1H NMR spectroscopy. Ligand precursors, polyethylene glycol esters of nicotinic ( L1 · 2HCl– L4 · 2HCl and L9 · HCl) and isonicotinic acid dihydrochlorides ( L5 · 2HCl– L8 · 2HCl), binuclear ruthenium(II) complexes 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 and mononuclear complex 9 were tested for in vitro cytotoxicity against 518A2 (melanoma), 8505C (anaplastic thyroid cancer), A253 (head and neck tumour), MCF‐7 (breast tumour) and SW480 (colon carcinoma) cell lines. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

11.
Using a relative kinetic technique, rate coefficients have been measured, at 296 ± 2 K and 740 Torr total pressure of synthetic air, for the gas‐phase reaction of OH radicals with the dibasic esters dimethyl succinate [CH3OC(O)CH2CH2C(O)OCH3], dimethyl glutarate [CH3OC(O)CH2CH2CH2C(O)OCH3], and dimethyl adipate [CH3OC(O)CH2CH2CH2CH2C(O)OCH3]. The rate coefficients obtained were (in units of cm3 molecule?1 s?1): dimethyl succinate (1.89 ± 0.26) × 10?12; dimethyl glutarate (2.13 ± 0.28) × 10?12; and dimethyl adipate (3.64 ± 0.66) × 10?12. Rate coefficients have been also measured for the reaction of chlorine atoms with the three dibasic esters; the rate coefficients obtained were (in units of cm3 molecule?1 s?1): dimethyl succinate (6.79 ± 0.93) × 10?12; dimethyl glutarate (1.90 ± 0.33) × 10?11; and dimethyl adipate (6.08 ± 0.86) × 10?11. Dibasic esters are industrial solvents, and their increased use will lead to their possible release into the atmosphere, where they may contribute to the formation of photochemical air pollution in urban and regional areas. Consequently, the products formed from the oxidation of dimethyl succinate have been investigated in a 405‐L Pyrex glass reactor using Cl‐atom–initiated oxidation as a surrogate for the OH radical. The products observed using in situ Fourier transform infrared (FT‐IR) absorption spectroscopy and their fractional molar yields were: succinic formic anhydride (0.341 ± 0.068), monomethyl succinate (0.447 ± 0.111), carbon monoxide (0.307 ± 0.061), dimethyl oxaloacetate (0.176 ± 0.044), and methoxy formylperoxynitrate (0.032–0.084). These products account for 82.4 ± 16.4% C of the total reaction products. Although there are large uncertainties in the quantification of monomethyl succinate and dimethyl oxaloacetate, the product study allows the elucidation of an oxidation mechanism for dimethyl succinate. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 431–439, 2001  相似文献   

12.
Germatranes bearing a ferrocenylalkoxyl moiety have been obtained by the reaction of HOGe(OCH2CH2)3N with various ferrocenyl alcohols. A convenient new synthesis method of FcCH2OGe(OCH2CH2)3N was reported. FcCH2OGe(OCH2CH2)3N was prepared in 93% yield when FcCH2OH reacted with HOGe(OCH2CH2)3N in chloroform at room temperature in the presence of molecular sieves (3 Å) as a dehydrating agent. All compounds were characterized by elemental analysis, 1H NMR and IR spectroscopy. The molecular structures of FcCH2OGe(OCH2CH2)3N and FcCH(CH3)OGe(OCH2CH2)3N have been determined by X‐ray diffraction. The antitumor activities of FcCH2OGe(OCH2CH2)3N and p‐FcC6H4CH2OGe(OCH2CH2)3N were determined. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

13.
Vibrational Spectra and Force Constants of the Series OP(CH3)3? OP(OCH3)3 and SP(CH3)3? SP(OCH3)3 The vibrational spectra of OP(CH3)2(OCH3), OP(CH3)(OCH3)2, SP(CH3)2(OCH3), and SP(CH3)(OCH3)2, are recorded and assigned to the normal vibration. The valence force constants are calculated by a simplified force field. The results are disscussed for both series and compared with former results.  相似文献   

14.
Sodium bis[2‐(3′,6′,9′‐trioxadecyl)‐1,2‐dicarba‐closo‐dodecaborane‐1‐carboxylato]triphenylstannate, [(CH3OCH2CH2OCH2CH2OCH2CH2)‐1,2‐C2B10H10‐9‐COO)2SnPh3]? Na+, compound 1, was synthesized by the 1:1 condensation of triphenyltin(IV) hydroxide with 2‐(3′,6′,9′‐trioxadecyl)‐1,2‐dicarba‐closo‐dodecaborane‐1‐carboxylic acid and crystallized in the presence of sodium bicarbonate. Its structure was determined by spectroscopy, elemental analysis and X‐ray diffraction. The structure of 1 consists of trigonal bipyramidal [Sn(Ph)3(L)2]? anions and Na+ cations coordinated by oxygen atoms of polyoxaalkyl chains of different stannate anions, forming cation–anion chains elongated along the c axis. Compound 1 is significantly more active in vitro against seven tumour cell lines of human origin than 5‐fluorouracil, cis‐platin, carboplatin, and previously reported organotin carboranecarboxylates, but is less active than organotin polyoxaalkylcarboxylates. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   

15.
The synthesis of various phosphoranimines including (CH3OCH2CH2O) (CF3CH2O)2P?N? Si(CH3)3, (CH3OCH2CH2OCH2CH2O) (CF3CH2O)2P?N? Si (CH3)3, (CH3OCH2CH2O)2(CF3CH2O) P?N? Si(CH3)3, and (CH3OCH2CH2OCH2CH2O)(CF3CH2O) P?N? Si(CH3)3 via the Staudinger reaction of (CH3)3SiN3 with the suitably substituted phosphite is reported. These monomers were polymerized using tetra-n-butylammonium fluoride and N-methylimidazole in various solvents at several temperatures. In situ 31P-NMR kinetic studies and Mn versus time studies were also performed for the monomers to understand the propagation mechanism. © 1994 John Wiley & Sons, Inc.  相似文献   

16.
The results of high-pressure variable-temperature and variable ionizing electron energy studies of gas-phase ion-molecule reactions of dimethyl ether in krypton are presented. Near the ionization threshold a series of peaks corresponding to (CH3OCH3)nH+ (n = 1-4) clusters are observed. At higher ionizing electron energies, two new series of peaks appear, corresponding to [CH3OCH2]+(CH3OCH3)n and [(CH3)3O]+ (CH3OCH3)n clusters. The onium ion, [(CH3)3O]+, has been previously reported at elevated temperatures under methane chemical ionization conditions. It was suggested that the onium ion is formed by reaction of (CH3)2OH+ with CH3OCH3 with subsequent elimination of methanel, i.e. by fragmentation of an adduct ion. The present results strongly suggest that, under our conditions, [CH3OCH2]+ rather than thermal (CH3)3OH+, is the precursor to [(CH3)3O]+.  相似文献   

17.
The products of the gas‐phase reactions of the OH radical with n‐butyl methyl ether and 2‐isopropoxyethanol in the presence of NO have been investigated at 298 ± 2 K and 740 Torr total pressure of air by gas chromatography and in situ atmospheric pressure ionization tandem mass spectrometry. The products observed from n‐butyl methyl ether were methyl formate, propanal, butanal, methyl butyrate, and CH3C(O)CH2CH2OCH3 and/or CH3CH2C(O)CH2OCH3, with molar formation yields of 0.51 ± 0.11, 0.43 ± 0.06, 0.045 ± 0.010, ∼0.016, and 0.19 ± 0.04, respectively. Additional products of molecular weight 118, 149 and 165 were observed by API‐MS/MS analyses, with those of molecular weight 149 and 165 being identified as organic nitrates. The products observed and quantified from 2‐isopropoxyethanol were isopropyl formate and 2‐hydroxyethyl acetate, with molar formation yields of 0.57 ± 0.05 and 0.44 ± 0.05, respectively. For both compounds, the majority of the reaction products and reaction pathways are accounted for, and detailed reaction mechanisms are presented. The results of this product study are combined with previous literature product data to investigate the tropospheric reactions of R1R2C(Ȯ)OR radicals formed from ethers and glycol ethers, leading to a revised estimation method for the calculation of reaction rates of alkoxy radicals. © 1999 John Wiley & Sons, Inc. Int J Chem Kinet 31: 501–513, 1999  相似文献   

18.
The tetrameric Cu(β-diketonate) alkoxide complex [Cu(thd)(OCH2CH2OCH3)]4 (thd = 2,2,6,6-tetramethyl-3,5-heptanedionate; 1a ) reacts with the alkaline earth metal alkoxides [M(OCH2CH2OCH3)2] (M = Ca, 2a ; M = Sr, 2b ; M = Ba, 2c ) to yield the heteronuclear compounds [Cu2M(thd)3(OCH2CH2OCH3)3] (M = Ca, 6a ; M = Sr, 6b ). These heterometallic complexes were also obtained in the reaction of 1a and the mixed Ca and Sr complexes of β-diketonate-alkoxide [Mx(thd)y(OCH2CH2OCH3)2x?y] (M = Ca, x = 7, y = 6, 3 ; M = Sr, x = 5, y = 3, 4 ), respectively. In comparison, 1a reacts with the analogous [Ba(thd)(OCH2CH2OCH3)] ( 5a ) to yield a[Ba2Cu2(thd)4(OCH3)4(HOCH2CH2OCH3)2] species ( 8a .) The in situ prepared mixed-ligand Ba Compounds [Ba(thd)OR)] (R = CH2CH2OCH2CH2OCH3, ( 5b ); R = CH2CH2CH2OCH3 ( 5c ) react with the corresponding Cu complexes [Cu(thd)(OR)]n (R = CH2CH2OCH2CH2OCH3), n = 4 ( 1b ); R = CH2CH2OCH2CH2OCH3 ( 8b ); R = CH2CH2CH2OCH3 ( 8c ). However, [Cu(hfd)(OCH2CH2OCH3)]4 (hfd = 1,1,1,5,5,5,-hexafluoroacetylacetonate; 1e ) is converted in the presence of 2a–c to the simple metathesis products [M(hfd)2] (M = Ca, Sr, Ba) and [Cu(OCH2CH2OCH3)2]. Crystalline [Ba2Cu2(hfd)2(thd)2(OCH2CH2CH2OCH3)4(HOCH2CH2CH2OCH3)2] ( 9 ) was isolated from the reaction of 1a with in situ prepared [Ba((hfd)OCH2CH2CH2OCH3)] ( 5d ) in 2-, methoxyethanol. X-Ray crystallographic structure determinations are reported for 6a , 6b , 8b , and 8c .  相似文献   

19.
Alternative Ligands. XXX Novel Tripod Ligands XM' (OCH2PMe2)n(CH2CH2PMe2)3?n (M' = Si, Ge; n = 0–3) for Cage Structures Attempts to prepare new tripod ligands XSi(OCH2PMe2)3 [X = CF3 ( 15 ), C6F5 ( 16 ), NMe2 ( 17 ), Cl ( 18 ), F ( 19 ), H ( 20 ), OEt ( 21 ), OMe ( 22 )] prove to be unsuccessful in spite of using different pathways, because the groups X undergo following reactions giving insoluble solids (polyadducts) or form inseparable mixtures, e. g. (RO)nSi(OCH2PMe2)4?n (R = Me, Et). In many cases Si(OCH2PMe2)4 ( 13 ) can be isolated from the reaction mixture. The syntheses of the ligands XSi(CH2CH2PMe2)3 [X = NMe2 ( 6 ), Cl ( 7 ), F ( 8 ), OMe ( 9 ), Vi ( 12 )], Si(OCH2PMe2)4 ( 13 ) und Me3GeOCH2PMe2 ( 14 ) are successful. The compounds MeSi(OCH2PMe2)2CH2CH2NMe2 ( 10 ) and MeSi(OCH2PMe2)2CH2CH2P(CF3)2 ( 11 ) with different donor groups are obtained in good yields. The preparative program includes the synthesis of the known representatives MeSi(OCH2PMe3)3 ( 1 ), MeSi(OCH2PMe2)2CH2CH2PMe2 ( 2 ), MeSi(OCH2PMe2)(CH2CH2PMe2)2 ( 3 ), MeSi(CH2CH2PMe2)3 ( 4 ) and MeGe(OCH2PMe2)3 ( 5 ). Important preparative steps are the substitution of M'Cl (M' = Si, Ge) by Me2PCH2O groups and the photochemically induced or base catalyzed addition of HNMe2, HPMe2 or HP(CF3)2 to SiVi functions. The novel compounds are characterized by analytical and spectroscopic (IR, NMR, MS) investigations.  相似文献   

20.
New Metallatranes of Transition Elements: Chloro- and Cyclopentadienyltitatrane and Chloro- and Acetatozirconatrane Synthesis and characterization of chloro- and cyclopentadienyltitatrane, [ClTi(OCH2CH2)3N]2 and [CpTi(OCH2CH2)3N], and of chloro- and acetatozirconatrane, [ClZr(OCH2CH2)3N]n and [CH3CO2Zr(OCH2CH2)3N]2, as well are described as new types of metallatranes of transition elements.  相似文献   

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