Effect of Diamine in Amine-Functionalized MIL-101 for Knoevenagel Condensation

Notes Bull. Korean Chem. Soc. 2011, Vol. 32, No. 6 2073

DOI10.5012/bkcs.2011.32.6.2073 Effect of Diamine in Amine-Functionalized MIL-101 for Knoevenagel Condensation

Palraj Kasinathan,?,? You-Kyong Seo,? Kyu-Eun Shim,?,? Young Kyu Hwang,?,?,* U-Hwang Lee,?,* Dong Won Hwang,?

Do-Young Hong,? Shiva B. Halligudi,? and Jong-San Chang?,?

?Research Group for Nanocatalyst, Korea Research Institute of Chemical Technology, Daejeon 305-600, Korea

*E-mail: ykhwang@krict.re.kr(Y. K. H); uhwang@krict.re.kr(U-H. L)

?School of Science, University of Science and Technology (UST), Daejeon, 305-333, Korea

Received February 28, 2011, Accepted April 6, 2011

Key Words : MOF, MIL-101, Pore size, Coordinativ ely unsaturated metal sites (CUS), Knoev enagel

condensation

Crystalline Metal-Organic Frameworks (MOFs) are current-ly an important kind of advanced functional materials due to their novel coordination structures, diverse topologies, and potential applications.1-5 As one of topical M OFs, porous chromium terephthalate with giant pores labeled M IL-101(Cr) possesses several unique features such as hierar-chical pore structure6 including a mesoporous zeotype architecture, mesoporous cages and microporous windows, outstanding sorption properties, numerous unsaturated metal cation sites,and high hydrothermal and chemical stability. These properties have led to a number of application potential in catalysis, gas storage, drug delivery and adsorptive separation.7-10 One important challenge has to realize is funtionalization via incorporation of binding site or reactive centers for catalysis. The functionalization methods of metal organic frameworks (MOFs) in a wide range of applications are two possible approaches including pre- and post-modification with functional groups.7,9-15

The functionalized pores of MOFs can be used as active sites in base-catalyzed reactions.13,16-19 It was already described on an electrophilic surface functionalization of coordinatively unsaturated metal sites (CUS) with chelating agents or electron-rich molecules. M IL-101(Cr) may thus be finely tuned for catalytic applications in precise conditions. It is known that MIL-101(Cr) possesses two coordinatively un-saturated metal sites (CUS) in a trimeric Cr(III) octahedral cluster (Scheme 1) with terminal water molecules which are removable from the framework under vacuum or in an inert gas flow at 423 K for 12 h. This CUS as Lewis acid sites in the structure was usable for the surface functionalization7 (Figure 1).

Here we further explore the preparation of the amine-

grafted MIL-101 as a heterogeneous base catalyst according

to a p K a value of the functional diamine group and their catalytic activities in Knoevenagel condensation of benz-

aldehyde and ethylcynoacetate. The diamine compounds

used for the functionalization include ethane-1,2-diamine

(ED), butane-1,4-diamine (BD), decane-1,10-diamine (DD)

and benzene-1,4-diamine (PD).

The XRD patterns of functionalized samples show de-

crease of intensity. These results provide that the diamines

were filled the pores of MIL-101. However, the patterns still

show the high-crystalline frameworks and porous structures

after functionalization. (Supplementary M aterials, Figure

S1) The structural details of the pores such as BET surface

area, pore volume and pore size are exhibited in Supple-

mentary Materials (Figure S2 and Table S1). Figure 1 shows

the N2 adsorption isotherms of as-prepared and function-

alized MIL-101. The as-prepared MIL-101 has BET surface

area of 4035 m2/g and pore volume of 1.96 cm3/g. After

functionalization, the surface areas and pore volumes are

decreased with change of the functional groups because the

different sizes of diamines are attached to the pore surfaces

and partially block the pores. It corresponds with the decrease

of adsorbed N2

amount gradually with the functionalization. Scheme 1. Evolution of coordinatively unsaturated Cr(III) sites

from chromium trimer after vacuum treatment 423 K for 12 h.

Figure 1. Nitrogen adsorption isotherms of MIL-101 and amine-

grafted MIL-101 at 77 K: (a) purified MIL-101, (b) ED-MIL-101,

(c) PD-MIL-101, (d) BD-MIL-101, and (e) DD-MIL-101.

2074 Bull. Korean Chem. Soc . 2011, Vol. 32, No. 6

Notes

However, the shapes of the isotherm curves were not changed after functionalization (Fig. 1). The XRD and BET results revealed that the porous framework of M IL-101 is very stable during the functionalization process. From pore size distribution profiles calculated from adsorption branch of N 2-isotherms (Fig. S2), MIL-101 has two-types of meso-pores centered in 1.9/1.4 nm, respectively. The pore sizes of functionalized samples also decreased, as increased number of hydrocarbons (HC) of grafted amines. As a result, DD-MIL-101 has pores of 1.6/1.0 nm, respectively. On the other hand, small molecules functionalized samples as ED-MIL-101 are not shown noticeable change in pore size distribu-tion. Additionally, nitrogen contents obtained by elemental analysis (EA) were 2.1 mmol/g (ED-MIL-101), 1.9 mmol/g (BD-MIL-101), 1.4 mmol/g (PD-MIL-101) and 1.3 mmol/g (DD-MIL-101), respectively. Although the DD-MIL-101 has smallest number of nitrogen contents, it has small pores due to the long chain of DD filled the pores. PD-MIL-101 also has small number of nitrogen content because their weak electronegativity of phenyl amine group acted as to be impediment to amine functionalization at the CUS sites. In addition, this result could be main reason of PD-M IL-101showing higher surface area than the BD-MIL-101 in spite of longer HC chain.

For the proof of amine-functionalization, the FT-IR spectra (Fig. S3) were measured at 433 K after the removal of solvent and water contents. The result shows a typical band of -NH (3150-3400 cm ?1) and -CH (2800-3000 cm ?1) stretch-ing vibration modes as marked in Figure S3. However, the PD-MIL-101 does not possess -CH band and it shows a shift in the -NH band due to primary amine attached to aromatic ring of PD. (dash-circle) The peak of left-shifted -CH stretch-ing vibrations of BD- and ED-MIL-101 were appeared by neighboring aliphatic -CH of bonded amine to Lewis acid Cr sites. These results demonstrated the selective functionali-zation of diamines into the pores of MIL-101.15 The strong intensity of the -CH stretching band of DD-M IL-101 is appeared by long chain length of DD.

The catalytic activities of the amine functionalized MIL-101 in the Knoevenagel condensation of benzaldehyde and ethyl cynoacetate are shown in Figure 2. To confirm the effect of diamine on base catalysis, the reaction was carried out under less reactive condition using toluene as a solvent and lower temperature of 333 K. The samples have high

selectivity (>99%) to trans-ethyl cyanocinnamate at the conversion ranges between 45 to 98% by different basicities as p K a values 21 of functional group. The condensation reac-tions were carried out to probe the effect of basicity of the active sites which were created by diamines in the pores of M IL-101. The reactivity of the samples shows correlation with the p K a values of the diamines. BD-MIL-101 has the high reactivity as shown in Figure 2 and Table 1. The reac-tivity of BD-MIL-101 was both found to be high conversion of 98% and turn over frequency (TOF) of 5.7. The higher activity attributed to high p K a value of the functional group.The reactivity of ED-MIL-101 and PD-MIL-101 with lower p K a values is lower than BD- and DD- functionalized samples.Although ED-M IL-101 still has large pore size and high surface area, it shows low conversion activity of 89% and TOF value of 3.5 because ED- is not high p K a value. The PD-M IL-101 has lower p K a value of 6.08 due to the delocalization of lone pair of electrons on nitrogen. Hence,the PD-M IL-101 has the lowest basicity and the lowest catalytic activity as conversion activity of 44.8% and TOF valve of 1.4. However, DD-M IL-101 with higher p K a of 11.00 shows lower conversion activity of 82%. The lower reactivity of DD-MIL-101 attributed to the less number of basic sites for the reaction as well as the longest chain length of hindered diffusion of the reactant molecules. Moreover,the amine of the long carbon chain might be has hydrogen bond with adjacent amines or the free amine group can graft with the neighboring CUS sites.22

In conclusion, we have demonstrated that amines with different basicities successfully functionalized into the pores of M IL-101 and amine functionalized chromium terephth-alate used as a base catalyst. The catalytic activity of amine functionalized M IL-101 in Knoevenagel condensation of ethylcyanoacetate and benzaldehyde depends on their basi-cities. The reactivity of these catalytic materials could be also affected by their pore size and/or surface area, which governs the facile diffusion of the molecules through the

Table 1. Catalytic activities of amine-g rafted MIL-101(Cr) in Knoevenagel condensation of benzaldehyde with ethyl cynoacetate a

C atalyst p K a Conv. (%)b Sel. (%)c TOF (h ?1)d ED-MIL-1018.668999 3.5BD-MIL-10110.409899 5.7DD-MIL-10111.008299 5.6PD-MIL-101

6.08

45

99

1.4

a The reaction was carried out at same condition as described in Figure 2.b

Conversion of benzaldehyde at 15 h. c Selectivity towards trans -ethyl cyanoacetate. d TOF (turn over frequency): moles of product formed per mole of nitrogen in the grafted MIL-101 per hour (measured at 2 h).

Figure 2. Conversion of benzaldehyde as a function of reaction time over amine-g rafted MIL-101 in

Knoevenag el condensation.The reaction was carried out with 1 mmol of benzaldehyde, 1mmol of ethylcynoacetate, 30 mg of catalyst and 25 mL of toluene heated at 333 K.

Notes Bull. Korean Chem. Soc. 2011, Vol. 32, No. 6 2075

channels of the MIL-101. The present strategy ensures the development of new functionalities and lead to MOF appli-cations of practically useful heterogeneous base catalysts for chemical transformations.

Experimental Section

The MIL-101 was synthesized by a hydrothermal reaction of terephthalic acid with Cr(NO3)3·9H2O, HF, and H2O at 493 K in 8 h according to the procedure proposed by our previous report.7,9 The as-synthesized MIL-101 was further purified by a three-step process using double filtration, hot ethanol, and aqueous NH4F solutions.The purified MIL-101 (0.5 g) was dehydrated at 423 K for 12 h and then suspended in anhydrous toluene (30 mL). 1.5 mmol of ED, BD, DD and PD were added individually and the mixture was stirred under reflux for 12 h in nitrogen environment. The function-alized MIL-101s or samples? were tested for their catalytic activities in the Knovenagel condensation reaction. The reaction was carried out with 1 mmol of benzaldehyde, 1 mmol of ethylcynoacetate, 30mg of catalyst and 25 mL of toluene heated at 333 K.

Acknowledgments. This research was supported by the Pioneer Research Center Program through the National Research Foundation of Korea funded by the M inistry of Education, Science and Technology (2011-0001667/2011-0001669) and the Korea Research Foundation Grant funded by the Korean Government (357-2008-1-C00070). The authors thank Prof. Gerard Ferey, and Dr. Christian Serre for their helpful discussion.

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Notes

Bull. Korean Chem. Soc . 2011, Vol. 32, No. 6 1

DOI 10.5012/bkcs.2011.32.6.

Effect of Diamine in Amine-Functionalized MIL-101 for Knoevenagel Condensation

Palraj Kasinathan,?,? You-Kyong Seo,? Kyu-Eun Shim,?,? Young Kyu Hwang,?,?,* U-Hwang Lee,?,* Dong Won Hwang,?

Do-Young Hong,? Shiva B. Halligudi,? and Jong-San Chang ?,?

?

Research Group for Nanocatalyst, Korea Research Institute of Chemical Technology, Daejeon 305-600, Korea

*

E-mail: ykhwang@krict.re.kr

?

School of Science, University of Science and Technology (UST), Daejeon, 305-333, Korea

Received February 28, 2011, Accepted April 6, 2011

Table S1. Physicochemical properties of as-prepared and function-alized MIL-101 samples Sample a N content (mmolg ?1)b

S BET (m 2g ?1)c P.V (cm 3g ?1)d PSD (nm)e MIL-101(Cr)-4035 1.96 1.9/1.4ED-MIL-101 2.13101 1.49 1.8/1.3PD-MIL-101 1.42981 1.44 1.7/1.2BD-MIL-101 1.92603 1.21 1.6/1.1DD-MIL-101

1.3

2446

1.17

1.6/1.0

a

ED, BD, DD and PD are abbreviation of ethane-1,2-diamine, butane-1,4-diamine, decane-1,10-diamine and benzene-1,4-diamine, respec-tively. b Determined from Elemental analysis. c Surface area evaluated using the Brunauer-Emmett-Teller (BET) method from the N 2 adsorption isotherm. d Pore volume taken by a single point method at p/p 0 = 0.99.e

Pore size distribution values are obtained by the BJH equation.

Figure S1. XRD patte rns of (a) as-pre pare d Porous chromium te re phthalate (MIL-101(Cr)) and (b-e ) amine s functionalize d samples; (b) ethane-1,2-diamine (ED-MIL-101) (c) butane-1,4-diamine (BD-MIL-101) (d) decane-1,10-diamine (DD-MIL-101)and (e) benzene-1,4-diamine (PD-MIL-101), respectively.

Figure S2. Pore-size distribution curves with adsorption volume and pore diameter. (a) as-prepared MIL-101, (b) ED-MIL-101, (c)PD-MIL-101, (d) BD-MIL-101 and (e ) DD-MIL-101, re spe c-

tively.

Figure S3. FT-IR Spe ctra of amine functionalize d MIL-101sample s at 473 K. (a) DD-MIL-101, (c) BD-MIL-101, (d) ED-MIL-101 and (e) PD-MIL-101.

英语中的比较级与最高级 详解

比较级与最高级 1.as...as 与(not) as(so)...as as...as...句型中，as的词性 第一个as是副词，用在形容词和副词的原级前，常译为“同样地”。第二个as是连词，连接与前面句子结构相同的一个句子(相同部分常省略)，可译为“同..... He is as tall as his brother is (tall) . (后面的as 为连词) 只有在否定句中，第一个as才可换为so 改错: He is so tall as his brother.（X） 2.在比较状语从句中，主句和从句的句式结构一般是相同的 与as...as 句式中第二个as一样，than 也是连词。as和than这两个连词后面的从句的结构与前面的句子大部分情况下结构是相同的，相同部分可以省略。 He picked more apples than she did. 完整的表达为: He picked more apples than she picked apples. 后而的picked apples和前面相同，用did 替代。 He walked as slowly as she did.完整表达为: He walked as slowly as she walked slowly. she后面walked slowly与前面相同，用did替代。

3.谓语的替代 在as和than 引导的比较状语从句中，由于句式同前面 主句相同，为避免重复，常把主句中出现而从句中又出现的动词用do的适当形式来代替。 John speaks German as fluently as Mary does. 4.前后的比较对象应一致 不管后面连词是than 还是as,前后的比较对象应一致。The weather of Beijing is colder than Guangzhou. x than前面比较对象是“天气”，than 后面比较对象是“广州”，不能相比较。应改为: The weather of Bejing is colder than that of Guangzhou. 再如: His handwriting is as good as me. 应改为: His handwriting is as good as mine. 5.可以修饰比较级的词 常用来修饰比较级的词或短语有: Much,even,far,a little,a lot,a bit,by far,rather,any,still,a great deal等。 by far的用法: 用于强调，意为“...得多”“最最...”“显然”等，可修饰形容词或副词的比较级和最高级，通常置于其后，但是若比较级或最高级前有冠词，则可置于其前或其后。

The way常见用法

The way 的用法 Ⅰ常见用法： 1)the way+ that 2)the way + in which（最为正式的用法） 3)the way + 省略（最为自然的用法） 举例：I like the way in which he talks. I like the way that he talks. I like the way he talks. Ⅱ习惯用法： 在当代美国英语中，the way用作为副词的对格，“the way+ 从句”实际上相当于一个状语从句来修饰整个句子。 1)The way =as I am talking to you just the way I’d talk to my own child. He did not do it the way his friends did. Most fruits are naturally sweet and we can eat them just the way they are—all we have to do is to clean and peel them. 2）The way= according to the way/ judging from the way The way you answer the question, you are an excellent student. The way most people look at you, you’d think trash man is a monster. 3）The way =how/ how much No one can imagine the way he missed her. 4）The way =because

人教版(新目标)初中英语形容词与副词的比较级与最高级

人教版（新目标）初中英语形容词与副词的比较级与最高级 （一）规则变化： 1．绝大多数的单音节和少数双音节词，加词尾-er ，-est tall—taller—tallest 2．以不发音的e结尾的单音节词和少数以-le结尾的双音节词只加-r，-st nice—nicer—nicest , able—abler—ablest 3．以一个辅音字母结尾的重读闭音节词或少数双音节词，双写结尾的辅音字母，再加-er，-est big—bigger—biggest 4．以辅音字母加y结尾的双音节词，改y为i再加-er，-est easy—easier—easiest 5．少数以-er，-ow结尾的双音节词末尾加-er，-est clever—cleverer—cleverest, narrow—narrower—narrowest 6．其他双音节词和多音节词，在前面加more，most来构成比较级和最高级 easily—more easily—most easily （二）不规则变化 常见的有： good / well—better—best ; bad (ly)/ ill—worse—worst ; old—older/elder—oldest/eldest many / much—more—most ; little—less—least ; far—farther/further—farthest/furthest

用法： 1．原级比较：as + adj./adv. +as（否定为not so/as + adj./adv. +as）当as… as中间有名字时，采用as + adj. + a + n.或as + many / much + n. This is as good an example as the other is . I can carry as much paper as you can. 表示倍数的词或其他程度副词做修饰语时放在as的前面 This room is twice as big as that one. 倍数+as+adj.+as = 倍数+the +n.+of Your room is twice as larger as mine. = Your room is twice the size of mine. 2．比较级+ than 比较级前可加程度状语much, still, even, far, a lot, a little, three years. five times,20%等 He is three years older than I (am). 表示“（两个中）较……的那个”时，比较级前常加the（后面有名字时前面才能加冠词） He is the taller of the two brothers. / He is taller than his two brothers. Which is larger, Canada or Australia? / Which is the larger country, Canada or Australia? 可用比较级形式表示最高级概念，关键是要用或或否定词等把一事物（或人）与其他同类事物（或人）相分离 He is taller than any other boy / anybody else.

英语中的比较级和最高级

大多数形容词有三种形式,原级,比较级和最高级, 以表示形容词说明的性质在程度上的不同。 形容词的原级: 形容词的原级形式就是词典中出现的形容词的原形。例如: poor tall great glad bad 形容词的比较级和最高级: 形容词的比较级和最高级形式是在形容词的原级形式的基础上变化的。分为规则变化和不规则变化。 规则变化如下: 1) 单音节形容词的比较级和最高级形式是在词尾加 -er 和 -est 构成。 great (原级) (比较级) (最高级) 2) 以 -e 结尾的单音节形容词的比较级和最高级是在词尾加 -r 和 -st 构成。wide (原级) (比较级) (最高级) 3)少数以-y, -er, -ow, -ble结尾的双音节形容词的比较级和最高级是在词尾加 -er 和 -est 构成。 clever(原级) (比较级) (最高级) 4) 以 -y 结尾,但 -y 前是辅音字母的形容词的比较级和最高级是把 -y 去掉,加上 -ier 和-est 构成. happy (原形) (比较级) (最高级) 5) 以一个辅音字母结尾其前面的元音字母发短元音的形容词的比较级和最高级是双写该辅音字母然后再加 -er和-est。 big (原级) (比较级) (最高级) 6) 双音节和多音节形容词的比较级和最高级需用more 和 most 加在形容词前面来构成。 beautiful (原级) (比较级) (比较级) difficult (原级) (最高级) (最高级) 常用的不规则变化的形容词的比较级和最高级: 原级------比较级------最高级 good------better------best many------more------most much------more------most bad------worse------worst far------farther, further------farthest, furthest 形容词前如加 less 和 least 则表示"较不"和"最不 形容词比较级的用法: 形容词的比较级用于两个人或事物的比较,其结构形式如下: 主语+谓语(系动词)+ 形容词比较级+than+ 对比成分。也就是, 含有形容词比较级的主句+than+从句。注意从句常常省去意义上和主句相同的部分, 而只剩下对比的成分。

The way的用法及其含义(二)

The way的用法及其含义（二） 二、the way在句中的语法作用 the way在句中可以作主语、宾语或表语： 1.作主语 The way you are doing it is completely crazy.你这个干法简直发疯。 The way she puts on that accent really irritates me. 她故意操那种口音的样子实在令我恼火。The way she behaved towards him was utterly ruthless. 她对待他真是无情至极。 Words are important, but the way a person stands, folds his or her arms or moves his or her hands can also give us information about his or her feelings. 言语固然重要,但人的站姿,抱臂的方式和手势也回告诉我们他(她)的情感。 2.作宾语 I hate the way she stared at me.我讨厌她盯我看的样子。 We like the way that her hair hangs down.我们喜欢她的头发笔直地垂下来。 You could tell she was foreign by the way she was dressed. 从她的穿著就可以看出她是外国人。 She could not hide her amusement at the way he was dancing. 她见他跳舞的姿势，忍俊不禁。 3.作表语 This is the way the accident happened.这就是事故如何发生的。 Believe it or not, that's the way it is. 信不信由你, 反正事情就是这样。 That's the way I look at it, too. 我也是这么想。 That was the way minority nationalities were treated in old China. 那就是少数民族在旧中

英语比较级和最高级的用法归纳

英语比较级和最高级的用法归纳 在学习英语过程中，会遇到很多的语法问题，比如比较级和最高级的用法，对于 这些语法你能够掌握吗？下面是小编整理的英语比较级和最高级的用法，欢迎阅读！ 英语比较级和最高级的用法 一、形容词、副词的比较级和最高级的构成规则 1.一般单音节词和少数以-er，-ow结尾的双音节词，比较级在后面加-er，最高级 在后面加-est; (1)单音节词 如：small→smaller→smallest short→shorter→shortest tall→taller→tallest great→greater→greatest (2)双音节词 如：clever→cleverer→cleverest narrow→narrower→narrowest 2.以不发音e结尾的单音节词，比较在原级后加-r，最高级在原级后加-st; 如：large→larger→largest nice→nicer→nicest able→abler→ablest 3.在重读闭音节(即：辅音+元音+辅音)中，先双写末尾的辅音字母，比较级加-er，最高级加-est; 如：big→bigger→biggest hot→hotter→hottest fat→fatter→fattest 4.以“辅音字母+y”结尾的双音节词，把y改为i，比较级加-er，最高级加-est; 如：easy→easier→easiest heavy→heavier→heaviest busy→busier→busiest happy→happier→happiest 5.其他双音节词和多音节词，比较级在前面加more，最高级在前面加most; 如：bea utiful→more beautiful→most beautiful different→more different→most different easily→more easily→most easily 注意：(1)形容词最高级前通常必须用定冠词 the，副词最高级前可不用。 例句： The Sahara is the biggest desert in the world. (2) 形容词most前面没有the，不表示最高级的含义，只表示"非常"。 It is a most important problem. =It is a very important problem.

(完整版)the的用法

定冠词the的用法： 定冠词the与指示代词this ,that同源,有“那(这)个”的意思,但较弱,可以和一个名词连用,来表示某个或某些特定的人或东西. (1)特指双方都明白的人或物 Take the medicine.把药吃了. (2)上文提到过的人或事 He bought a house.他买了幢房子. I've been to the house.我去过那幢房子. (3)指世界上独一无二的事物 the sun ,the sky ,the moon, the earth (4)单数名词连用表示一类事物 the dollar 美元 the fox 狐狸 或与形容词或分词连用,表示一类人 the rich 富人 the living 生者 (5)用在序数词和形容词最高级,及形容词等前面 Where do you live?你住在哪? I live on the second floor.我住在二楼. That's the very thing I've been looking for.那正是我要找的东西. (6)与复数名词连用,指整个群体 They are the teachers of this school.(指全体教师) They are teachers of this school.(指部分教师) (7)表示所有,相当于物主代词,用在表示身体部位的名词前 She caught me by the arm.她抓住了我的手臂. (8)用在某些有普通名词构成的国家名称,机关团体,阶级等专有名词前 the People's Republic of China 中华人民共和国 the United States 美国 (9)用在表示乐器的名词前 She plays the piano.她会弹钢琴. (10)用在姓氏的复数名词之前,表示一家人 the Greens 格林一家人(或格林夫妇) (11)用在惯用语中 in the day, in the morning... the day before yesterday, the next morning... in the sky... in the dark... in the end... on the whole, by the way...

英语比较级和最高级的用法

More than的用法 A. “More than+名词”表示“不仅仅是” 1)Modern science is more than a large amount of information. 2)Jason is more than a lecturer; he is a writer, too. 3) We need more than material wealth to build our country.建设我们国家，不仅仅需要物质财富. B. “More than+数词”含“以上”或“不止”之意，如： 4)I have known David for more than 20 years. 5)Let's carry out the test with more than the sample copy. 6) More than one person has made this suggestion. 不止一人提过这个建议. C. “More than+形容词”等于“很”或“非常”的意思，如： 7)In doing scientific experiments, one must be more than careful with the instruments. 8)I assure you I am more than glad to help you. D. more than + (that)从句，其基本意义是“超过（=over）”，但可译成“简直不”“远非”.难以，完全不能（其后通常连用情态动词can） 9) That is more than I can understand . 那非我所能懂的. 10) That is more than I can tell. 那事我实在不明白。 11) The heat there was more than he could stand. 那儿的炎热程度是他所不能忍受的 此外，“more than”也在一些惯用语中出现，如： more...than 的用法 1. 比……多，比……更 He has more books than me. 他的书比我多。 He is more careful than the others. 他比其他人更仔细。 2. 与其……不如 He is more lucky than clever. 与其说他聪明，不如说他幸运。 He is more （a）scholar than （a）teacher. 与其说他是位教师，不如说他是位学者。 注：该句型主要用于同一个人或物在两个不同性质或特征等方面的比较，其中的比较级必须用加more 的形式，不能用加词尾-er 的形式。 No more than/not more than 1. no more than 的意思是“仅仅”“只有”“最多不超过”，强调少。如： --This test takes no more than thirty minutes. 这个测验只要30分钟。 --The pub was no more than half full. 该酒吧的上座率最多不超过五成。-For thirty years，he had done no more than he （had）needed to. 30年来，他只干了他需要干的工作。 2. not more than 为more than （多于）的否定式，其意为“不多于”“不超过”。如：Not more than 10 guests came to her birthday party. 来参加她的生日宴会的客人不超过十人。 比较： She has no more than three hats. 她只有3顶帽子。（太少了） She has not more than three hats. 她至多有3顶帽子。（也许不到3顶帽子） I have no more than five yuan in my pocket. 我口袋里的钱最多不过5元。（言其少） I have not more than five yuan in my pocket. 我口袋里的钱不多于5元。（也许不到5元） more than, less than 的用法 1. （指数量）不到，不足 It’s less than half an hour’s drive from here. 开车到那里不到半个钟头。 In less than an hour he finished the work. 没要上一个小时，他就完成了工作。 2. 比……（小）少 She eats less than she should. 她吃得比她应该吃的少。 Half the group felt they spent less than average. 半数人觉得他们的花费低于平均水平。 more…than,/no more than/not more than (1)Mr．Li is ________ a professor; he is also a famous scientist． (2)As I had ________ five dollars with me, I couldn’t afford the new jacket then． (3)He had to work at the age of ________ twelve． (4)There were ________ ten chairs in the room．However, the number of the children is twelve． (5)If you tel l your father what you’ve done, he’ll be ________ angry． (6)－What did you think of this novel? －I was disappointed to find it ________ interesting ________ that one． 倍数表达法 1. “倍数+形容词（或副词）的比较级+than+从句”表示“A比B大（长、高、宽等）多少倍” This rope is twice longer than that one.这根绳是那根绳的三倍（比那根绳长两倍）。The car runs twice faster than that truck.这辆小车的速度比那辆卡车快两倍（是那辆卡车的三倍）。 2. “倍数+as+形容词或副词的原级+as+从句”表示“A正好是B的多少倍”。

“the way+从句”结构的意义及用法

“tｈｅwａｙ+从句”结构的意义及用法 首先让我们来看下面这个句子: Ｒead the foｌloｗｉnｇpassagｅａnd talkａbout ｉt wi ｔh your classmaｔes．Try tｏｔeｌl whaｔyｏu thiｎk ｏf Tom aｎd ｏｆｔhe ｗay the chiｌｄrenｔrｅated ｈim. 在这个句子中，ｔhe waｙ是先行词,后面是省略了关系副词that或in whｉch的定语从句。 下面我们将叙述“the ｗaｙ+从句”结构的用法。 1.tｈe wａy之后，引导定语从句的关系词是tｈat而不是hoｗ,因此，<<现代英语惯用法词典＞＞中所给出的下面两个句子是错误的：Ｔhｉs is ｔｈeｗayｈowｉtｈａppened. This is the way how he ａlwａｙs treats me. 2．在正式语体中,thaｔ可被in which所代替;在非正式语体中，ｔhat则往往省略。由此我们得到theｗay后接定语从句时的三种模式：1) tｈe ｗaｙ＋ｔhａt-从句２）the way +ｉn whiｃh－从句3) the ｗay +从句 例如：Ｔｈe way(in whiｃh ，thａt) ｔhｅｓｅｃomｒade ｓloｏｋａｔｐrobｌems is wrong．这些同志看问题的方法

不对。 Ｔｈｅｗａy(that ,ｉn ｗhiｃh)yoｕ’ｒe doinｇit is comple ｔeｌy crａzy.你这么个干法,简直发疯。 Wｅａdmiｒｅd him for thｅｗay ｉｎｗhｉch he fａｃeｓdiｆficultieｓ． Waｌlａｃe ａｎd Ｄarwiｎｇreed ｏn the way ｉｎwhi ｃh ｄｉfｆｅrｅnt forms ｏf life had ｂegｕn.华莱士和达尔文对不同类型的生物是如何起源的持相同的观点。 Thｉs is ｔｈe ｗaｙ（tｈａｔ) hｅdｉd it. I lｉkeｄｔhe waｙ(ｔhat) ｓｈeｏｒganized ｔhe ｍeetｉng． 3.theｗay(tｈat)有时可以与hｏw(作“如何”解）通用。例如： That’s tｈe ｗaｙ(tｈaｔ) shｅspoke. = Tｈat’s how shｅspoke.

初中英语比较级和最高级讲解与练习

初中英语比较级和最高级讲解与练习 形容词比较级和最高级 一．绝大多数形容词有三种形式,原级,比较级和最高级, 以表示形容词说明的性质在程度上的不同。 1. 形容词的原级: 形容词的原级形式就是词典中出现的形容词的原形。例如: poor tall great glad bad 2. 形容词的比较级和最高级: 形容词的比较级和最高级形式是在形容词的原级形式的基 础上变化的。分为规则变化和不规则变化。 二．形容词比较级和最高级规则变化如下: 1) 单音节形容词的比较级和最高级形式是在词尾加-er 和-est 构成。 great (原级) greater(比较级) greatest(最高级) 2) 以-e 结尾的单音节形容词的比较级和最高级是在词尾加-r 和-st 构成。 wide (原级) wider (比较级) widest (最高级) 3) 少数以-y, -er, -ow, -ble结尾的双音节形容词的比较级和最高级是在词尾加 -er 和-est构成。 clever(原级) cleverer(比较级) cleverest(最高级)， slow(原级) slower(比较级) slowest (最高级) 4) 以-y 结尾,但-y 前是辅音字母的形容词的比较级和最高级是把-y 去掉,加上-ier 和-est 构成. happy (原形) happier (比较级) happiest (最高级) 5) 以一个辅音字母结尾其前面的元音字母发短元音的形容词的比较级和最高级是双写该 辅音字母然后再加-er和-est。 原形比较级最高级原形比较级最高级 big bigger biggest hot hotter hottest red redder reddest thin thinner thinnest 6) 双音节和多音节形容词的比较级和最高级需用more 和most 加在形容词前面来构 成。 原形比较级最高级 careful careful more careful most careful difficult more difficult most difficult delicious more delicious most delicious 7)常用的不规则变化的形容词的比较级和最高级: 原级比较级最高级 good better best 好的 well better best 身体好的 bad worse worst 坏的 ill worse worst 病的 many more most 许多 much more most 许多 few less least 少数几个 little less least 少数一点儿 （little littler littlest 小的） far further furthest 远（指更进一步，深度。亦可指更远） far farther farthest 远（指更远，路程）

way 用法

表示“方式”、“方法”，注意以下用法： 1.表示用某种方法或按某种方式，通常用介词in(此介词有时可省略)。如： Do it (in) your own way. 按你自己的方法做吧。 Please do not talk (in) that way. 请不要那样说。 2.表示做某事的方式或方法，其后可接不定式或of doing sth。 如： It’s the best way of studying [to study] English. 这是学习英语的最好方法。 There are different ways to do [of doing] it. 做这事有不同的办法。 3.其后通常可直接跟一个定语从句(不用任何引导词)，也可跟由that 或in which 引导的定语从句，但是其后的从句不能由how 来引导。如： 我不喜欢他说话的态度。 正：I don’t like the way he spoke. 正：I don’t like the way that he spoke. 正：I don’t like the way in which he spoke. 误：I don’t like the way how he spoke. 4.注意以下各句the way 的用法： That’s the way (=how) he spoke. 那就是他说话的方式。 Nobody else loves you the way(=as) I do. 没有人像我这样爱你。 The way (=According as) you are studying now, you won’tmake much progress. 根据你现在学习情况来看，你不会有多大的进步。 2007年陕西省高考英语中有这样一道单项填空题： ——I think he is taking an active part insocial work. ——I agree with you_____. A、in a way B、on the way C、by the way D、in the way 此题答案选A。要想弄清为什么选A，而不选其他几项，则要弄清选项中含way的四个短语的不同意义和用法，下面我们就对此作一归纳和小结。 一、in a way的用法 表示：在一定程度上，从某方面说。如： In a way he was right.在某种程度上他是对的。注：in a way也可说成in one way。 二、on the way的用法 1、表示：即将来(去)，就要来(去)。如： Spring is on the way.春天快到了。 I'd better be on my way soon.我最好还是快点儿走。 Radio forecasts said a sixth-grade wind was on the way.无线电预报说将有六级大风。 2、表示：在路上，在行进中。如： He stopped for breakfast on the way.他中途停下吃早点。 We had some good laughs on the way.我们在路上好好笑了一阵子。 3、表示：(婴儿)尚未出生。如： She has two children with another one on the way.她有两个孩子，现在还怀着一个。 She's got five children，and another one is on the way.她已经有5个孩子了，另一个又快生了。 三、by the way的用法

英语比较级和最高级

形容词比较级和最高级的形式 一、形容词比较级和最高级的构成 形容词的比较级和最高级变化形式规则如下 构成法原级比较级最高级 ①一般单音节词末尾加 er 和 est strong stronger strongest ②单音节词如果以 e结尾，只加 r 和 st strange stranger strangest ③闭音节单音节词如末尾只有一个辅音字母， 须先双写这个辅音字母，再加 er和 est sad big hot sadder bigger hotter saddest biggest hottest ④少数以 y, er(或 ure), ow, ble结尾的双音节词， 末尾加 er和 est(以 y结尾的词，如 y前是辅音字母， 把y变成i，再加 er和 est，以 e结尾的词仍 只加 r和 st) angry Clever Narrow Noble angrier Cleverer narrower nobler angriest cleverest narrowest noblest ⑤其他双音节和多音节词都在前面加单词more和most different more different most different 1) The most high 〔A〕mountain in 〔B〕the world is Mount Everest，which is situated 〔C〕in Nepal and is twenty nine thousand one hundred and fourty one feet high 〔D〕 . 2) This house is spaciouser 〔A〕than that 〔B〕white 〔C〕one I bought in Rapid City，South Dakota 〔D〕last year. 3) Research in the social 〔A〕sciences often proves difficulter 〔B〕than similar 〔C〕work in the physical 〔D〕sciences. 二、形容词比较级或最高级的特殊形式：

高中英语的比较级和最高级用法总结

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The way的用法及其含义(一)

The way的用法及其含义（一） 有这样一个句子：In 1770 the room was completed the way she wanted. 1770年，这间琥珀屋按照她的要求完成了。 the way在句中的语法作用是什么？其意义如何？在阅读时，学生经常会碰到一些含有the way 的句子，如：No one knows the way he invented the machine. He did not do the experiment the way his teacher told him.等等。他们对the way 的用法和含义比较模糊。在这几个句子中，the way之后的部分都是定语从句。第一句的意思是，“没人知道他是怎样发明这台机器的。”the way的意思相当于how；第二句的意思是，“他没有按照老师说的那样做实验。”the way 的意思相当于as。在In 1770 the room was completed the way she wanted.这句话中，the way也是as的含义。随着现代英语的发展，the way的用法已越来越普遍了。下面，我们从the way的语法作用和意义等方面做一考查和分析： 一、the way作先行词，后接定语从句 以下3种表达都是正确的。例如：“我喜欢她笑的样子。” 1. the way+ in which +从句 I like the way in which she smiles. 2. the way+ that +从句 I like the way that she smiles. 3. the way + 从句(省略了in which或that) I like the way she smiles. 又如：“火灾如何发生的，有好几种说法。” 1. There were several theories about the way in which the fire started. 2. There were several theories about the way that the fire started.

(完整版)初中英语比较级和最高级的用法

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