s*n
2 楼
A Research Associate position is available for the investigation of novel
materials for polymer membrane fuel cells and further optimisation of the
fuel cell performance.
The successful candidate will have or about to obtain a PhD in a relevant
area of chemistry or materials science. Applicants with demonstrated
experiences in synthesis of ion exchange or ionic conducting polymer
membranes, particularly anion exchange membranes are welcome. Some basic
knowledge in fuel cells or electrochemistry,
materials for polymer membrane fuel cells and further optimisation of the
fuel cell performance.
The successful candidate will have or about to obtain a PhD in a relevant
area of chemistry or materials science. Applicants with demonstrated
experiences in synthesis of ion exchange or ionic conducting polymer
membranes, particularly anion exchange membranes are welcome. Some basic
knowledge in fuel cells or electrochemistry,
n*g
3 楼
☆─────────────────────────────────────☆
JGG (五月的花&五月的海) 于 (Thu May 7 15:11:38 2009) 提到:
太FT了。
被杀的那个人,我都不认识。。。晕死。。。
而且后来又活过来了。。。
这个梦莫名其妙。。。做了很久,情节很复杂,跟看电影一样。。。
☆─────────────────────────────────────☆
bonalove (bonalove) 于 (Thu May 7 15:16:33 2009) 提到:
这个我不会解哈,我倒是梦到抱得美人归了。
☆─────────────────────────────────────☆
JGG (五月的花&五月的海) 于 (Thu May 7 15:19:48 2009) 提到:
恭喜,恭喜。
☆─────────────────────────────────────☆
bonalove (bonalove) 于 (Thu May 7 15:30:01 2009) 提到:
醒来的时候很痛苦啊,一声叹息
☆
JGG (五月的花&五月的海) 于 (Thu May 7 15:11:38 2009) 提到:
太FT了。
被杀的那个人,我都不认识。。。晕死。。。
而且后来又活过来了。。。
这个梦莫名其妙。。。做了很久,情节很复杂,跟看电影一样。。。
☆─────────────────────────────────────☆
bonalove (bonalove) 于 (Thu May 7 15:16:33 2009) 提到:
这个我不会解哈,我倒是梦到抱得美人归了。
☆─────────────────────────────────────☆
JGG (五月的花&五月的海) 于 (Thu May 7 15:19:48 2009) 提到:
恭喜,恭喜。
☆─────────────────────────────────────☆
bonalove (bonalove) 于 (Thu May 7 15:30:01 2009) 提到:
醒来的时候很痛苦啊,一声叹息
☆
o*1
4 楼
靠
g*z
5 楼
集显的主板稍小,内部有更多空间用于散热,只有一个风扇
独显的主板上有显存,多一个风扇,CPU风扇靠左,元件排列完全不同了。
独显的主板上有显存,多一个风扇,CPU风扇靠左,元件排列完全不同了。
k*r
6 楼
下了10.04的iso,做成bootable USB disk, 运行wubi安装,居然显示要7小时.
按理系统应该都在USB上了, 还去网络上pull什么东西呢?
按理系统应该都在USB上了, 还去网络上pull什么东西呢?
f*o
7 楼
Download Instructions: Map ID: 2044
http://ifile.it/t1yfadv
http://rapidshare.com/files/272418686/2044.zip.html
Unzip password : gmapsupp
Credit goes to grmntt from pda4x
http://ifile.it/t1yfadv
http://rapidshare.com/files/272418686/2044.zip.html
Unzip password : gmapsupp
Credit goes to grmntt from pda4x
m*e
8 楼
http://pubs.acs.org/doi/abs/10.1021/ja904224y
Reductive and Transition-Metal-Free: Oxidation of Secondary Alcohols by Sodium Hydride
Xinbo Wang, Bo Zhang and David Zhigang Wang*
School of Chemical Biology and Biotechnology, Shenzhen Graduate School of Peking University, Shenzhen, China 518055
Abstract
The potential utilities of the simplest hydride reductant sodium hydride (NaH) as an oxidation promoter have long been overlooked. Uncovered here are some unprecedented reactivities of this classic
Reductive and Transition-Metal-Free: Oxidation of Secondary Alcohols by Sodium Hydride
Xinbo Wang, Bo Zhang and David Zhigang Wang*
School of Chemical Biology and Biotechnology, Shenzhen Graduate School of Peking University, Shenzhen, China 518055
Abstract
The potential utilities of the simplest hydride reductant sodium hydride (NaH) as an oxidation promoter have long been overlooked. Uncovered here are some unprecedented reactivities of this classic
a*9
9 楼
谢谢。有人提供些意见吗?
综合学校,地理,将来就业机会。等因素。
综合学校,地理,将来就业机会。等因素。
y*5
12 楼
算不上ground breaking. 挺有意思的结果。
g*z
14 楼
第二张是我拍的。第一张是notebookcheck.com的。是个高配15'的测评里的。
m*e
16 楼
Well, let's take Uemura's Pd(OAc)2/py system as an example. It is nothing
fundamentally new. But those with sharp chemical intuition (Sherman, Sigman,
Stoltz etc.) still sensed the opportunities and quickly jumped onto that
chemistry. An important field was thus created. I believe some people will
not have any problem to call Uemura's discovery as a ground-breaking one.
If Wang's results (substrate scope, full recovery of NaH etc.) can be
confirmed by other groups, it will build the basis for a
【在 y****5 的大作中提到】
: 算不上ground breaking. 挺有意思的结果。
fundamentally new. But those with sharp chemical intuition (Sherman, Sigman,
Stoltz etc.) still sensed the opportunities and quickly jumped onto that
chemistry. An important field was thus created. I believe some people will
not have any problem to call Uemura's discovery as a ground-breaking one.
If Wang's results (substrate scope, full recovery of NaH etc.) can be
confirmed by other groups, it will build the basis for a
【在 y****5 的大作中提到】
: 算不上ground breaking. 挺有意思的结果。
w*i
17 楼
这么早就出来了 我还没申请呢 额
p*m
20 楼
It's really interesting outstanding work if it's reproducible.
a*9
25 楼
南加大现在不是很水吗?
给了好多AD..
西北名气大些。
给了好多AD..
西北名气大些。
l*5
27 楼
请倭杂狗不要上中国人的bbs,谢谢!
t*e
28 楼
很漂亮的工作。只能说我和伊一起吃过饭.....
a*9
29 楼
考虑就业的话。。西北?南加大?
考虑回国的话呢?
毕竟西北声誉好一些
考虑回国的话呢?
毕竟西北声誉好一些
g*z
30 楼
本来还以为2.53G 09是直接阉割版,没想主板这么大差别
a*w
32 楼
不可思议的结果,操作简单,没有重金属污染,NaH全部回收,副产物是氢气,经济性
和实用性非常强。确实是突破性的发现。肯定会有很多人重复这个工作。有点担心的是
国产的NaH纯度怎么会,会不会含有重金属在里面,作者又没有买aldrich的或者别的公
司的NaH重复这个实验结果。
和实用性非常强。确实是突破性的发现。肯定会有很多人重复这个工作。有点担心的是
国产的NaH纯度怎么会,会不会含有重金属在里面,作者又没有买aldrich的或者别的公
司的NaH重复这个实验结果。
p*e
35 楼
机理没看明白,谁能详细解释一下这个反应,谁是氧化剂,谁是还原剂,按机理是不是
只需要催化量的NaH?
只需要催化量的NaH?
l*a
40 楼
虚拟机安装很快啊
默认选英文试试,可能其他语言要下语言包
默认选英文试试,可能其他语言要下语言包
t*u
41 楼
很不错,怪不得我用NaH做的反应得不到产品。
c*e
44 楼
读master,只要承受得起学费,location是王道。绝对USC的干活儿。
H*r
46 楼
USC
and,NW isn't that cheap either i guess
and,NW isn't that cheap either i guess
h*y
48 楼
当然USC
t*u
49 楼
thanks,fun to read
【在 d**n 的大作中提到】
: http://totallysynthetic.com/blog/?p=1903
: http://www.coronene.com/blog/?p=842
【在 d**n 的大作中提到】
: http://totallysynthetic.com/blog/?p=1903
: http://www.coronene.com/blog/?p=842
a*9
54 楼
谢谢阿。各位。
n*t
55 楼
就是作者偏向的第一个机理:金属钠应该也可以有同样的中间体啊。怪怪的。
不论是不是a ground-breaking discovery, 很多认都在关注。
http://totallysynthetic.com 里面的讨论很有趣。
【在 d**n 的大作中提到】
: 同意,作者提了两个机理,感觉都不符合化学常识。
: 第一个benzylic的H作为hydride给Na
: 第二个醇羟基的质子作为hydride给Na
不论是不是a ground-breaking discovery, 很多认都在关注。
http://totallysynthetic.com 里面的讨论很有趣。
【在 d**n 的大作中提到】
: 同意,作者提了两个机理,感觉都不符合化学常识。
: 第一个benzylic的H作为hydride给Na
: 第二个醇羟基的质子作为hydride给Na
s*m
56 楼
用屁股想想都USC,毕业几乎没有找不到工作 的。
b*y
58 楼
俺最好奇的是这个热力学上是可行的吗?
按照作者的说法,整个净反应就是
醇--> 酮 + H2
delta G是正是负?
似乎酮的氢化在催化剂条件下(Pd啊什么)是应该可以发生的;那就
是说相反的过程不自发,在热力学上这个反应就不可能?
哪位大侠分析一下。
Sodium Hydride
Peking University, Shenzhen, China 518055
NaH) as an oxidation promoter have long been overlooked. Uncovered here are
some unprecedented reactivities of this classical reagent under very mild
conditions, including alcohol oxidation, tandem allylic alcohol oxidation
8722;hydride conjugate reduction, and aldehyde oxidative amidation. These
readily implem
【在 m*****e 的大作中提到】
: http://pubs.acs.org/doi/abs/10.1021/ja904224y
: Reductive and Transition-Metal-Free: Oxidation of Secondary Alcohols by Sodium Hydride
: Xinbo Wang, Bo Zhang and David Zhigang Wang*
: School of Chemical Biology and Biotechnology, Shenzhen Graduate School of Peking University, Shenzhen, China 518055
: Abstract
: The potential utilities of the simplest hydride reductant sodium hydride (NaH) as an oxidation promoter have long been overlooked. Uncovered here are some unprecedented reactivities of this classic
按照作者的说法,整个净反应就是
醇--> 酮 + H2
delta G是正是负?
似乎酮的氢化在催化剂条件下(Pd啊什么)是应该可以发生的;那就
是说相反的过程不自发,在热力学上这个反应就不可能?
哪位大侠分析一下。
Sodium Hydride
Peking University, Shenzhen, China 518055
NaH) as an oxidation promoter have long been overlooked. Uncovered here are
some unprecedented reactivities of this classical reagent under very mild
conditions, including alcohol oxidation, tandem allylic alcohol oxidation
8722;hydride conjugate reduction, and aldehyde oxidative amidation. These
readily implem
【在 m*****e 的大作中提到】
: http://pubs.acs.org/doi/abs/10.1021/ja904224y
: Reductive and Transition-Metal-Free: Oxidation of Secondary Alcohols by Sodium Hydride
: Xinbo Wang, Bo Zhang and David Zhigang Wang*
: School of Chemical Biology and Biotechnology, Shenzhen Graduate School of Peking University, Shenzhen, China 518055
: Abstract
: The potential utilities of the simplest hydride reductant sodium hydride (NaH) as an oxidation promoter have long been overlooked. Uncovered here are some unprecedented reactivities of this classic
a*w
59 楼
y*e
62 楼
碱性、亲核性、还原性三者有相当大差别
NaH, NaNH2都是强碱性、弱亲核性、弱还原性
NaH基本不还原有机物
NaH, NaNH2都是强碱性、弱亲核性、弱还原性
NaH基本不还原有机物
a*w
63 楼
m*x
65 楼
maybe THF gets oxidized and thus act as the oxidant
m*e
66 楼
I just checked the standard reaction free energy for the conversion of
isopropanol
to acetone and dihydrogen. Surprisingly, it is only about 6 kcal/mol at room
temperature. That means dehydrogenations of those substrates in Wang's
paper should be at least nearly thermoneutral due to the extra conjugation
effect in the products. So the reaction free energies might be fine in Wang'
s
cases.
However, even if the standard free reaction energy is positive , the
thermodynamic
problem might still be ov
【在 b**y 的大作中提到】
: 你说的没错,氢化一般都是在H2大大过量的情况下发生的。。。。如果是1:1就不知道
: 了;
: 不过你后面说的要是用 氢acceptor 代替氢气,反应就变了:不管氢acceptor是THF还
: 是O2,净反应就不同了。
isopropanol
to acetone and dihydrogen. Surprisingly, it is only about 6 kcal/mol at room
temperature. That means dehydrogenations of those substrates in Wang's
paper should be at least nearly thermoneutral due to the extra conjugation
effect in the products. So the reaction free energies might be fine in Wang'
s
cases.
However, even if the standard free reaction energy is positive , the
thermodynamic
problem might still be ov
【在 b**y 的大作中提到】
: 你说的没错,氢化一般都是在H2大大过量的情况下发生的。。。。如果是1:1就不知道
: 了;
: 不过你后面说的要是用 氢acceptor 代替氢气,反应就变了:不管氢acceptor是THF还
: 是O2,净反应就不同了。
n*n
67 楼
的确是很有意思的实验结果,只是感觉作者有些急于发文章而对于机理的研究不够充分
。试剂纯度,金属离子,溶剂,反应温度等等都没做足够,或者没提供足够的筛选结果
,所以整个文章读起来感觉怪怪的。
而且根据这个实验结果,电子云密度大的aryloxide看上去都是不错的hydride donor
Sodium Hydride
Peking University, Shenzhen, China 518055
NaH) as an oxidation promoter have long been overlooked. Uncovered here are
some unprecedented reactivities of this classical reagent under very mild
conditions, including alcohol oxidation, tandem allylic alcohol oxidation
8722;hydride conjugate reduction, and aldehyde oxidative amidation. Thes
【在 m*****e 的大作中提到】
: http://pubs.acs.org/doi/abs/10.1021/ja904224y
: Reductive and Transition-Metal-Free: Oxidation of Secondary Alcohols by Sodium Hydride
: Xinbo Wang, Bo Zhang and David Zhigang Wang*
: School of Chemical Biology and Biotechnology, Shenzhen Graduate School of Peking University, Shenzhen, China 518055
: Abstract
: The potential utilities of the simplest hydride reductant sodium hydride (NaH) as an oxidation promoter have long been overlooked. Uncovered here are some unprecedented reactivities of this classic
。试剂纯度,金属离子,溶剂,反应温度等等都没做足够,或者没提供足够的筛选结果
,所以整个文章读起来感觉怪怪的。
而且根据这个实验结果,电子云密度大的aryloxide看上去都是不错的hydride donor
Sodium Hydride
Peking University, Shenzhen, China 518055
NaH) as an oxidation promoter have long been overlooked. Uncovered here are
some unprecedented reactivities of this classical reagent under very mild
conditions, including alcohol oxidation, tandem allylic alcohol oxidation
8722;hydride conjugate reduction, and aldehyde oxidative amidation. Thes
【在 m*****e 的大作中提到】
: http://pubs.acs.org/doi/abs/10.1021/ja904224y
: Reductive and Transition-Metal-Free: Oxidation of Secondary Alcohols by Sodium Hydride
: Xinbo Wang, Bo Zhang and David Zhigang Wang*
: School of Chemical Biology and Biotechnology, Shenzhen Graduate School of Peking University, Shenzhen, China 518055
: Abstract
: The potential utilities of the simplest hydride reductant sodium hydride (NaH) as an oxidation promoter have long been overlooked. Uncovered here are some unprecedented reactivities of this classic
n*t
69 楼
什么是hydride acceptor? Na+?
are
【在 n******n 的大作中提到】
: 的确是很有意思的实验结果,只是感觉作者有些急于发文章而对于机理的研究不够充分
: 。试剂纯度,金属离子,溶剂,反应温度等等都没做足够,或者没提供足够的筛选结果
: ,所以整个文章读起来感觉怪怪的。
: 而且根据这个实验结果,电子云密度大的aryloxide看上去都是不错的hydride donor
:
: Sodium Hydride
: Peking University, Shenzhen, China 518055
: NaH) as an oxidation promoter have long been overlooked. Uncovered here are
: some unprecedented reactivities of this classical reagent under very mild
: conditions, including alcohol oxidation, tandem allylic alcohol oxidation
are
【在 n******n 的大作中提到】
: 的确是很有意思的实验结果,只是感觉作者有些急于发文章而对于机理的研究不够充分
: 。试剂纯度,金属离子,溶剂,反应温度等等都没做足够,或者没提供足够的筛选结果
: ,所以整个文章读起来感觉怪怪的。
: 而且根据这个实验结果,电子云密度大的aryloxide看上去都是不错的hydride donor
:
: Sodium Hydride
: Peking University, Shenzhen, China 518055
: NaH) as an oxidation promoter have long been overlooked. Uncovered here are
: some unprecedented reactivities of this classical reagent under very mild
: conditions, including alcohol oxidation, tandem allylic alcohol oxidation
m*e
70 楼
Provided the current information, it is impossible to draw any firm
mechanistic conclusion. What can be said now is that oxygen can be
excluded as the stoichiometric oxidant for the reactions according
to their reaction procedure. (THF has been distilled from Na and the
reactions are protected under nitrogen. A trace amount of oxygen
might be absorbed on or in NaH, but I guess that would not be
enough to oxidize the alcohol to those high yields.)
Several obvious mechanistic possibilities can be
【在 d**n 的大作中提到】
: 同意,作者提了两个机理,感觉都不符合化学常识。
: 第一个benzylic的H作为hydride给Na
: 第二个醇羟基的质子作为hydride给Na
mechanistic conclusion. What can be said now is that oxygen can be
excluded as the stoichiometric oxidant for the reactions according
to their reaction procedure. (THF has been distilled from Na and the
reactions are protected under nitrogen. A trace amount of oxygen
might be absorbed on or in NaH, but I guess that would not be
enough to oxidize the alcohol to those high yields.)
Several obvious mechanistic possibilities can be
【在 d**n 的大作中提到】
: 同意,作者提了两个机理,感觉都不符合化学常识。
: 第一个benzylic的H作为hydride给Na
: 第二个醇羟基的质子作为hydride给Na
a*t
72 楼
Ru 催化剂 可以secondary alcohol to ketones,副产物是H2,不需要oxidants.
排除过渡金属杂质的因素,我比较倾向你说的第一种情况:(L)NaOR1R2 === > (L)NaH
+ ketones.
"Of course, the third one is the presence of a trace
amount of heavy metal impurity that actually catalyzes the reaction.
This option appears less likely to me because normally a reaction
like that needs to consume a stoichiometric amount of dioxygen
or other oxidants, which appears not available in Wang's reactions . "
【在 m*****e 的大作中提到】
: Provided the current information, it is impossible to draw any firm
: mechanistic conclusion. What can be said now is that oxygen can be
: excluded as the stoichiometric oxidant for the reactions according
: to their reaction procedure. (THF has been distilled from Na and the
: reactions are protected under nitrogen. A trace amount of oxygen
: might be absorbed on or in NaH, but I guess that would not be
: enough to oxidize the alcohol to those high yields.)
: Several obvious mechanistic possibilities can be
排除过渡金属杂质的因素,我比较倾向你说的第一种情况:(L)NaOR1R2 === > (L)NaH
+ ketones.
"Of course, the third one is the presence of a trace
amount of heavy metal impurity that actually catalyzes the reaction.
This option appears less likely to me because normally a reaction
like that needs to consume a stoichiometric amount of dioxygen
or other oxidants, which appears not available in Wang's reactions . "
【在 m*****e 的大作中提到】
: Provided the current information, it is impossible to draw any firm
: mechanistic conclusion. What can be said now is that oxygen can be
: excluded as the stoichiometric oxidant for the reactions according
: to their reaction procedure. (THF has been distilled from Na and the
: reactions are protected under nitrogen. A trace amount of oxygen
: might be absorbed on or in NaH, but I guess that would not be
: enough to oxidize the alcohol to those high yields.)
: Several obvious mechanistic possibilities can be
h*e
74 楼
我认为实验结果应该问题不大,顶多收率会有些出入。作者确实有些急于发文章而对于
机理基本没有研究,但作者若不提出这样的机理,而认为是NaH诱导的氧化机理,那光
凭这实验结果恐怕很难发JACS。我对作者提出的机理也甚感怀疑,我更倾向于氧化。至
于哪里来的氧,我认为有三个方面:空气中的氧,溶剂中的氧以及NaH吸附的氧。大部
分来自NaH吸附的氧,可能以NaOOH或NaOONa的形式存在。所以严格控制反应中混入的氧
应该会大大降低收率。同样我认为NaH在反应之后应该变成了NaOH,而不是可以回收,
也因此说明该反应需要超过当量的NaH。
are
【在 n******n 的大作中提到】
: 的确是很有意思的实验结果,只是感觉作者有些急于发文章而对于机理的研究不够充分
: 。试剂纯度,金属离子,溶剂,反应温度等等都没做足够,或者没提供足够的筛选结果
: ,所以整个文章读起来感觉怪怪的。
: 而且根据这个实验结果,电子云密度大的aryloxide看上去都是不错的hydride donor
:
: Sodium Hydride
: Peking University, Shenzhen, China 518055
: NaH) as an oxidation promoter have long been overlooked. Uncovered here are
: some unprecedented reactivities of this classical reagent under very mild
: conditions, including alcohol oxidation, tandem allylic alcohol oxidation
机理基本没有研究,但作者若不提出这样的机理,而认为是NaH诱导的氧化机理,那光
凭这实验结果恐怕很难发JACS。我对作者提出的机理也甚感怀疑,我更倾向于氧化。至
于哪里来的氧,我认为有三个方面:空气中的氧,溶剂中的氧以及NaH吸附的氧。大部
分来自NaH吸附的氧,可能以NaOOH或NaOONa的形式存在。所以严格控制反应中混入的氧
应该会大大降低收率。同样我认为NaH在反应之后应该变成了NaOH,而不是可以回收,
也因此说明该反应需要超过当量的NaH。
are
【在 n******n 的大作中提到】
: 的确是很有意思的实验结果,只是感觉作者有些急于发文章而对于机理的研究不够充分
: 。试剂纯度,金属离子,溶剂,反应温度等等都没做足够,或者没提供足够的筛选结果
: ,所以整个文章读起来感觉怪怪的。
: 而且根据这个实验结果,电子云密度大的aryloxide看上去都是不错的hydride donor
:
: Sodium Hydride
: Peking University, Shenzhen, China 518055
: NaH) as an oxidation promoter have long been overlooked. Uncovered here are
: some unprecedented reactivities of this classical reagent under very mild
: conditions, including alcohol oxidation, tandem allylic alcohol oxidation
d*n
77 楼
t*u
79 楼
why nobody here tried this reaction?
【在 d**n 的大作中提到】
: 结果出来了
: http://www.coronene.com/blog/?p=851#comments
【在 d**n 的大作中提到】
: 结果出来了
: http://www.coronene.com/blog/?p=851#comments
t*t
80 楼
不得不说不可思议
Sodium Hydride
Peking University, Shenzhen, China 518055
NaH) as an oxidation promoter have long been overlooked. Uncovered here are
some unprecedented reactivities of this classical reagent under very mild
conditions, including alcohol oxidation, tandem allylic alcohol oxidation
8722;hydride conjugate reduction, and aldehyde oxidative amidation. These
readily implementable transition-metal-free processes feature exceptional
material accessibility, operational simplicity, and : envir
【在 m*****e 的大作中提到】
: http://pubs.acs.org/doi/abs/10.1021/ja904224y
: Reductive and Transition-Metal-Free: Oxidation of Secondary Alcohols by Sodium Hydride
: Xinbo Wang, Bo Zhang and David Zhigang Wang*
: School of Chemical Biology and Biotechnology, Shenzhen Graduate School of Peking University, Shenzhen, China 518055
: Abstract
: The potential utilities of the simplest hydride reductant sodium hydride (NaH) as an oxidation promoter have long been overlooked. Uncovered here are some unprecedented reactivities of this classic
Sodium Hydride
Peking University, Shenzhen, China 518055
NaH) as an oxidation promoter have long been overlooked. Uncovered here are
some unprecedented reactivities of this classical reagent under very mild
conditions, including alcohol oxidation, tandem allylic alcohol oxidation
8722;hydride conjugate reduction, and aldehyde oxidative amidation. These
readily implementable transition-metal-free processes feature exceptional
material accessibility, operational simplicity, and : envir
【在 m*****e 的大作中提到】
: http://pubs.acs.org/doi/abs/10.1021/ja904224y
: Reductive and Transition-Metal-Free: Oxidation of Secondary Alcohols by Sodium Hydride
: Xinbo Wang, Bo Zhang and David Zhigang Wang*
: School of Chemical Biology and Biotechnology, Shenzhen Graduate School of Peking University, Shenzhen, China 518055
: Abstract
: The potential utilities of the simplest hydride reductant sodium hydride (NaH) as an oxidation promoter have long been overlooked. Uncovered here are some unprecedented reactivities of this classic
c*n
81 楼
不严谨, 被人抓住小辫子了。 看样子最根本的原因就是吸附氧
【在 d**n 的大作中提到】
: 结果出来了
: http://www.coronene.com/blog/?p=851#comments
【在 d**n 的大作中提到】
: 结果出来了
: http://www.coronene.com/blog/?p=851#comments
p*e
83 楼
这个结论比较靠谱,多谢分享。
【在 d**n 的大作中提到】
: 结果出来了
: http://www.coronene.com/blog/?p=851#comments
【在 d**n 的大作中提到】
: 结果出来了
: http://www.coronene.com/blog/?p=851#comments
d*2
84 楼
Much better experimental data than the following one.
Using the solution stabilized with 1 micro M melamine to assay the melamine
with the concentration in nano M range.
in
Hydrogen-Bonding Recognition-Induced Color Change of Gold Nanoparticles for
Visual Detection of Melamine in Raw Milk and Infant Formula
Kelong Ai, Yanlan Liu and Lehui Lu
pp 9496–9497
Publication Date (Web): June 18, 2009 (Communication)
DOI: 10.1021/ja9037017
Using the solution stabilized with 1 micro M melamine to assay the melamine
with the concentration in nano M range.
in
Hydrogen-Bonding Recognition-Induced Color Change of Gold Nanoparticles for
Visual Detection of Melamine in Raw Milk and Infant Formula
Kelong Ai, Yanlan Liu and Lehui Lu
pp 9496–9497
Publication Date (Web): June 18, 2009 (Communication)
DOI: 10.1021/ja9037017
c*n
85 楼
你已经拿这篇文章出来说了几十遍了.
melamine
for
【在 d****2 的大作中提到】
: Much better experimental data than the following one.
: Using the solution stabilized with 1 micro M melamine to assay the melamine
: with the concentration in nano M range.
: in
: Hydrogen-Bonding Recognition-Induced Color Change of Gold Nanoparticles for
: Visual Detection of Melamine in Raw Milk and Infant Formula
: Kelong Ai, Yanlan Liu and Lehui Lu
: pp 9496–9497
: Publication Date (Web): June 18, 2009 (Communication)
: DOI: 10.1021/ja9037017
melamine
for
【在 d****2 的大作中提到】
: Much better experimental data than the following one.
: Using the solution stabilized with 1 micro M melamine to assay the melamine
: with the concentration in nano M range.
: in
: Hydrogen-Bonding Recognition-Induced Color Change of Gold Nanoparticles for
: Visual Detection of Melamine in Raw Milk and Infant Formula
: Kelong Ai, Yanlan Liu and Lehui Lu
: pp 9496–9497
: Publication Date (Web): June 18, 2009 (Communication)
: DOI: 10.1021/ja9037017
d*2
86 楼
Because you are much smarter, you might not like those authors to detect the
analyte using the analyte. Is it crazy??
analyte using the analyte. Is it crazy??
m*e
87 楼
Looks like Wang et al did somehow contaminate their reactions with O2,
most likely by air leaking or from O2 absorption in NaH/mineral oil. The
next step should be to precisely measure the amount of oxygen that is
actually consumed in the reactions, to fully characterize the NaH before
and after the reactions as well as to double check if there is hydrogen
produced or not.
Wang's proposal might still be partially valid if only a catalytic amount
of O2 is consumed and a stoichiometric amount of h
【在 d**n 的大作中提到】
: 结果出来了
: http://www.coronene.com/blog/?p=851#comments
most likely by air leaking or from O2 absorption in NaH/mineral oil. The
next step should be to precisely measure the amount of oxygen that is
actually consumed in the reactions, to fully characterize the NaH before
and after the reactions as well as to double check if there is hydrogen
produced or not.
Wang's proposal might still be partially valid if only a catalytic amount
of O2 is consumed and a stoichiometric amount of h
【在 d**n 的大作中提到】
: 结果出来了
: http://www.coronene.com/blog/?p=851#comments
m*e
88 楼
Is there any way used in that case to continuously remove hydrogen, such
as refluxing or purging?
NaH
【在 a********t 的大作中提到】
: Ru 催化剂 可以secondary alcohol to ketones,副产物是H2,不需要oxidants.
: 排除过渡金属杂质的因素,我比较倾向你说的第一种情况:(L)NaOR1R2 === > (L)NaH
: + ketones.
: "Of course, the third one is the presence of a trace
: amount of heavy metal impurity that actually catalyzes the reaction.
: This option appears less likely to me because normally a reaction
: like that needs to consume a stoichiometric amount of dioxygen
: or other oxidants, which appears not available in Wang's reactions . "
as refluxing or purging?
NaH
【在 a********t 的大作中提到】
: Ru 催化剂 可以secondary alcohol to ketones,副产物是H2,不需要oxidants.
: 排除过渡金属杂质的因素,我比较倾向你说的第一种情况:(L)NaOR1R2 === > (L)NaH
: + ketones.
: "Of course, the third one is the presence of a trace
: amount of heavy metal impurity that actually catalyzes the reaction.
: This option appears less likely to me because normally a reaction
: like that needs to consume a stoichiometric amount of dioxygen
: or other oxidants, which appears not available in Wang's reactions . "
j*1
91 楼
How do they verify that NaH was 100% recovered? How do they know that what
they recovered was not say, a 1:1 mixture of NaOH and NaH? I don't have
access to the paper, I just can not figure out how.
【在 m*****e 的大作中提到】
: Looks like Wang et al did somehow contaminate their reactions with O2,
: most likely by air leaking or from O2 absorption in NaH/mineral oil. The
: next step should be to precisely measure the amount of oxygen that is
: actually consumed in the reactions, to fully characterize the NaH before
: and after the reactions as well as to double check if there is hydrogen
: produced or not.
: Wang's proposal might still be partially valid if only a catalytic amount
: of O2 is consumed and a stoichiometric amount of h
they recovered was not say, a 1:1 mixture of NaOH and NaH? I don't have
access to the paper, I just can not figure out how.
【在 m*****e 的大作中提到】
: Looks like Wang et al did somehow contaminate their reactions with O2,
: most likely by air leaking or from O2 absorption in NaH/mineral oil. The
: next step should be to precisely measure the amount of oxygen that is
: actually consumed in the reactions, to fully characterize the NaH before
: and after the reactions as well as to double check if there is hydrogen
: produced or not.
: Wang's proposal might still be partially valid if only a catalytic amount
: of O2 is consumed and a stoichiometric amount of h
p*r
92 楼
Wang was too eager to get a big paper and jumped to a jaw-dropping
conclusion without solid evidence. The last paragraph is especially amusing.
Compared to the author of the JOC paper (J. Org. Chem., 1965, 30 (7), pp
2433–2436), Wang is just childish.
conclusion without solid evidence. The last paragraph is especially amusing.
Compared to the author of the JOC paper (J. Org. Chem., 1965, 30 (7), pp
2433–2436), Wang is just childish.
c*n
93 楼
Wang挺牛的, 当初刚到哥大的时候就拿着自己的idea到处找老板, 最后这个idea做出来
了并上了CEN. 足以证明其实力.
不严谨下错结论其实也很常见. 我们这里一些洋男和华男, 滔滔不绝口若悬河, 这也
作不出来那也作不出来, 居然都能分析的头头是道逻辑上无懈可击令人叹服无话可说.
然而自己一试, 原因竟然只是伊懒惰无比, 原料没分纯就拿着往下跑而已.
amusing.
【在 p*****r 的大作中提到】
: Wang was too eager to get a big paper and jumped to a jaw-dropping
: conclusion without solid evidence. The last paragraph is especially amusing.
: Compared to the author of the JOC paper (J. Org. Chem., 1965, 30 (7), pp
: 2433–2436), Wang is just childish.
了并上了CEN. 足以证明其实力.
不严谨下错结论其实也很常见. 我们这里一些洋男和华男, 滔滔不绝口若悬河, 这也
作不出来那也作不出来, 居然都能分析的头头是道逻辑上无懈可击令人叹服无话可说.
然而自己一试, 原因竟然只是伊懒惰无比, 原料没分纯就拿着往下跑而已.
amusing.
【在 p*****r 的大作中提到】
: Wang was too eager to get a big paper and jumped to a jaw-dropping
: conclusion without solid evidence. The last paragraph is especially amusing.
: Compared to the author of the JOC paper (J. Org. Chem., 1965, 30 (7), pp
: 2433–2436), Wang is just childish.
k*m
94 楼
我怎么觉得楼主就是当事人啊
a*e
97 楼
I have heard something about how he transferred to 哥大 and how he found his
boss there. Very different from your story!
【在 c******n 的大作中提到】
: Wang挺牛的, 当初刚到哥大的时候就拿着自己的idea到处找老板, 最后这个idea做出来
: 了并上了CEN. 足以证明其实力.
: 不严谨下错结论其实也很常见. 我们这里一些洋男和华男, 滔滔不绝口若悬河, 这也
: 作不出来那也作不出来, 居然都能分析的头头是道逻辑上无懈可击令人叹服无话可说.
: 然而自己一试, 原因竟然只是伊懒惰无比, 原料没分纯就拿着往下跑而已.
:
: amusing.
boss there. Very different from your story!
【在 c******n 的大作中提到】
: Wang挺牛的, 当初刚到哥大的时候就拿着自己的idea到处找老板, 最后这个idea做出来
: 了并上了CEN. 足以证明其实力.
: 不严谨下错结论其实也很常见. 我们这里一些洋男和华男, 滔滔不绝口若悬河, 这也
: 作不出来那也作不出来, 居然都能分析的头头是道逻辑上无懈可击令人叹服无话可说.
: 然而自己一试, 原因竟然只是伊懒惰无比, 原料没分纯就拿着往下跑而已.
:
: amusing.
t*u
100 楼
3rd
X*l
101 楼
4th
p*e
102 楼
fifth
c*n
103 楼
6th
p*m
104 楼
7th
a*w
105 楼
8th
f*w
106 楼
9th
B*i
107 楼
10th
d*g
108 楼
11th
n*g
109 楼
12th
t*t
111 楼
沙发
t*u
112 楼
板凳
a*e
115 楼
已经被某人煽了!
不过不知道是因为没啥依据还是因为是私人话题!
不过名人是很难有隐私的。
不过不知道是因为没啥依据还是因为是私人话题!
不过名人是很难有隐私的。
t*u
117 楼
其实人家要的就是知名度,可惜斑竹给删了
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