Nanoputian

Systematic name
2-(4-{2-[3,5-bis(pent-1-yn-1-yl)phenyl]ethynyl}-2,5-bis(3,3-dimethylbut-1-yn-1-yl)phenyl)-1,3-dioxolane
Other names
1,3-dioxolane, 2-[2,5-bis(3,3-dimethyl-1-butyn-1-yl)-4-[2-(3,5-di-1-pentyn-1-ylphenyl)ethynyl]phenyl]
NanoKid
NanoPutian
618904-86-2  cas

NanoPutians are a series of organic molecules whose structural formulae resemble human forms.^[1] James Tour et al. (Rice University) designed and synthesized these compounds in 2003 as a part of a sequence of chemical education for young students.^[2] The compounds consist of two benzene rings connected via a few carbon atoms as the body, four acetylene units each carrying an alkyl group at their ends which represents the hands and legs, and a 1,3-dioxolane ring as the head. Tour and his team at Rice University used the NanoPutians in their NanoKids educational outreach program. The goal of this program was to educate children in the sciences in an effective and enjoyable manner. They have made several videos featuring the NanoPutians as anthropomorphic animated characters.

Construction of the structures depends on Sonogashira coupling and other synthetic techniques. By replacing the 1,3-dioxolane group with an appropriate ring structure, various other types of putians have been synthesized, e.g. NanoAthlete, NanoPilgrim, and NanoGreenBeret. Placing thiol functional groups at the leg enables them to "stand" on a gold surface.

"NanoPutian" is a portmanteau of nanometer, a unit of length commonly used to measure chemical compounds, and lilliputian, a fictional population of humans in the novel Gulliver's Travels.

Background

NanoKids Educational Outreach Program]

While there are no chemical uses for the NanoKid or any of its subsidiaries, James Tour has turned the NanoKid into a lifelike character to educate children in the sciences. The goals of the outreach program, as described on the NanoKids website, are:

• “To significantly increase students’ comprehension of chemistry, physics, biology, and materials science at the molecular level."
• "To provide teachers with conceptual tools to teach nanoscale science and emerging molecular technology."
• "To demonstrate that art and science can combine to facilitate learning for students with diverse learning styles and interests."
• "To generate informed interest in nanotechnology that encourages participation in and funding for research in the field.”^[3]

To accomplish these goals, several video clips, CDs, as well as interactive computer programs were created. Tour and his team invested over $250,000 into their project. In order to raise the funds for this endeavor, Tour used unrestricted funds from his professorship and small grants from Rice University, the Welch Foundation, the nanotech firm Zyvex, and Texas A&M University. Tour also received $100,000 in 2002 from the Small Grants for Exploratory Research program, a division of the National Science Foundation.^[4]

The main characters in the videos are animated versions of the NanoKid. They star in several videos and explain various scientific concepts, such as the periodic table, DNA, and covalent bonding.

Rice conducted several studies into the effectiveness of using the NanoKids materials. These studies found mostly positive results for the use of the NanoKids in the classroom. A 2004-2005 study in two schools districts in Ohio and Kentucky found that using NanoKids led to a 10-59% increase in understanding of the material presented. Additionally, it was found that 82% of students found that NanoKids made learning science more interesting.^[5]

Synthesis of NanoKid

Upperbody of NanoKid

To create the first NanoPutian, dubbed the NanoKid, 1,4-dibromobenzene was iodinated in sulfuric acid. To this product, “arms”, or 3,3-Dimethylbutyne, were then added through Sonogashira coupling. Formylation of this structure was then achieved through using the organolithium reagent n-butyllithium followed by quenching with N,N-dimethylformamide (DMF) to create the aldehyde. 1,2-Ethanediol was added to this structure to protect the aldehyde using p-toluenesulfonic acid as a catalyst. Originally, Chanteau and Tour aimed to couple this structure with alkynes, but this resulted in very low yields of the desired products. To remedy this, the bromide was replaced withiodide through lithium-halogen exchange and quenching by using 1,2-diiodoethane. This created the final structure of the upper body for the NanoKid.^[1]

Lowerbody of NanoKid

The synthesis of NanoPutian’s lower body begins with nitroaniline as a starting material. Addition of Br₂ in acetic acid places two equivalents of bromine on the benzene ring. NH₂ is an electron donating group, and NO₂ is an electron withdrawing group, which both direct bromination to the meta position relative to the NO₂ substituent. Addition of [[NaNO₂]], [[H₂SO₄]], and EtOH removes the NH₂¬ substituent. The Lewis acid SnCl₂, a reducing agent in THF/EtOH solvent, replaces NO₂ with NH₂, which is subsequently replaced by iodine upon the addition of NaNO₂, H₂SO₄, and KI to yield 3,5-dibromoiodobenzene. In this step, the Sandmeyer reaction converts the primary amino group (NH₂) to a diazonium leaving group (N₂), which is subsequently replaced by iodine. Iodine serves as an excellent coupling partner for the attachment of the stomach, which is executed through Sonogashira coupling with trimethylsilylacetylene to yield 3,5-dibromo(trimethylsilylethynyl)benzene. Attachment of the legs replaces the Br substituents with 1-pentyne through another Sonogashira coupling to produce 3,5-(1′-Pentynyl)-1-(trimethylsilylethynyl) benzene. To complete the synthesis of the lower body, the TMS protecting group is removed by selective deprotection through the addition of K₂CO₃, MeOH, and CH₂Cl₂ to yield 3,5-(1′-Pentynyl)-1-ethynylbenzene.^[1]

Attachment of Upperbody to Lowerbody of NanoKid

To attach the upper body of the NanoKid to the lower body, the two components were added to a solution of bis(triphenylphosphine)palladium(II) dichloride, copper(I) iodide,TEA, and THF. This resulted in the final structure of the NanoKid.^[1]

Derivatives of NanoKid

Synthesis of NanoProfessionals[]

The series of NanoProfessionals were created using the NanoKid as the starting material. This was done by adding an excess amount of a 1,2- or 1,3- diol to the NanoKid in the presence of a catalytic amount of p-toluenesulfonic acid and microwave oven-irradiation. The use of microwave irradiation reduced the reaction times. These reactions resulted in an acetal exchange, which changed the structure of the head of the NanoKid to create the different head structures of the NanoProfessionals, which include: NanoAthlete, NanoPilgrim, NanoGreenBeret, NanoJester, NanoMonarch, NanoTexan, NanoScholar, NanoBaker, and NanoChef. By creating a series of different figures, the ultimate product was a recognizably diverse population of NanoPutians.^[2]

Although the majority of the figures are depicted in their equilibrium conformations, some of the NanoPutians include nonequilibrium conformations in order to make them more recognizable to nonchemists. Many liberties were taken in the visual depiction of the head dressings of the NanoPutians.^[2]

The entire population of NanoPutians (with the exception of the NanoChef) were generated in one microwave oven reaction and confirmed by mass spectrometry and ¹HNMR.^[1]

Below is a table listing the diols needed to convert the NanoKid into various NanoProfessionals. The diols used to create NanoPilgrim and NanoTexan were made through reductive pinacol coupling of the 1,4- and 1,5-diketones with SmI₂ and Mg/TiCl₄. To create the diols used to make the NanoMonarch and the NanoScholar, catalytic OsO₄ was used to dihydroxylate the respective cycloalkenes. The diastereomeric ratios were determined through ¹H NMR using the diastereotopic acetal protons.^[1]

Synthesis of the NanoKid in Upright Form]

Stick Figure NanoPutian in its Energy Minimized Conformation. Determined Using Spartan.

3-Butyn-1-ol was reacted with methanesulfonyl chloride and triethanolamine to produce its mesylate. The mesylate was displaced to make thiolacetate. The thiol was coupled with 3,5-dibromo(trimethylsilylethynyl)benzene to create a free alkyne. The resulting product, 3,5-(4’-thiolacetyl-1’-butynyl)-1-(trimethylsilylethynyl)-benzene, had its trimethylsilyl group removed using tetra-n-butylammonium fluoride (TBAF) and AcOH/Ac₂O in THF. The free alkyne was then coupled with the upper body product from the earlier synthesis. This resulted in a NanoKid with protected thiol feet.^[1]

To make the NanoKid “stand’, the acetyl protecting groups were removed through the use of ammonium hydroxide in THF to create the free thiols. A gold-plated substrate was then dipped into the solution and incubated for four days. Ellipsometry was used to determine the resulting thickness of the compound, and it was determined that the NanoKid was upright on the substrate.^[1]

Synthesis of NanoPutian Chain

Synthesis of the upper part of the NanoPutian chain begins with 1,3-dibromo-2,4-diiodobenzene as the starting material. Sonogashira coupling with 4-oxytrimethylsilylbut-1-yne produces 2,5-bis(4-tert-butyldimethylsiloxy-1′-butynyl)-1,4-di-bromobenzene. One of the bromine substituents is converted to an aldehyde through an S_N2 reaction with the strong base, n-BuLi, and THF in the aprotic polar solvent, DMF to produce 2,5-bis(4-tert-butyldimethylsiloxy-1′-butynyl)-4-bromobenzaldehyde. Another Sonogashira coupling with 3,5-(1′-Pentynyl)-1-ethynylbenzene attaches the lower body of the NanoPutian. The conversion of the aldehyde group to a diether “head” occurs in two steps. The first step involves addition of ethylene glycol and trimethylsilyl chloride (TMSCl) in CH₂Cl₂ solvent. Addition of TBAF in THF solvent removes the silyl protecting group.^[1]

References

1. ^ ^{a b c d e f g h i} Chanteau, S. H.; Tour, J. M. (2003). "Synthesis of Anthropomorphic Molecules:  The NanoPutians". The Journal of Organic Chemistry 68 (23): 8750–8766.doi:10.1021/jo0349227. PMID 14604341. edit
2. ^ ^a b c Chanteau, S. H.; Ruths, T.; Tour, J. M. (2003). "Arts and Sciences Reunite in Nanoput: Communicating Synthesis and the Nanoscale to the Layperson". Journal of Chemical Education 80 (4): 395. doi:10.1021/ed080p395. edit
3. ^ “Welcome to Nanokids.” Accessed May 6, 2013. http://nanokids.rice.edu/.
4. ^ “C&EN: EDUCATION - ‘NANOKIDS’ TRY TO GET INTO MIDDLE SCHOOL.” Accessed May 10, 2013. http://pubs.acs.org/cen/education/8214/8214nanokids.html.
5. ^ “NanoKids - Mission.” Accessed May 6, 2013. http://cohesion.rice.edu/naturalsciences/nanokids/mission.cfm?doc_id=3039.

External link

http://cohesion.rice.edu/naturalsciences/nanokids/index.cfm

• http://pubs.acs.org/cen/education/8214/8214nanokids.html

In 2003, there was a paper published which looked like it was going to be a good candidate for the Ig Nobel Prize. It was “Synthesis of Anthropomorphic Molecules: The NanoPutians” by Professor James Tour, a chemistry professor at Rice University’s Institute for Nanoscale Science and Technology. The word “NanoPutian” is a portmanteau of “nano”, which means a billionth and the “Lilliputian” from the novel Gulliver’s Travels.
The Tour group designed and synthesized a number of human-shaped organic molecules in this paper. Shown in Figure 1 is a molecule named NanoKid, which was chosen by the group as a basic skeleton. The 3-D model looks like the figure on the right and the structural formula used by chemists is shown on the left. The structural formula might look more human, since the oxygen atoms look kind of like the eyes.

Fig 1 NanoKid

The functional group used for the head part of NanoKid is called acetal. This group is easily exchangeable to make NanoPutians of various occupations (Figure 2). Let’s not be too picky about the bond angles of NanoMonarch and NanoTexan.

Fig 2 various NanoPutians

Unfortunately, NanoBalletDancer seems to be the only one having a different posture (Figure 3). Personally, I would be interested in making NanoPitcher or NanoGermanSuplex!

Fig 3 NanoBalletDancer

The Tour Group also synthesized NanoPutians standing on gold surface with thiol functional groups on their feet, a NanoPutian couple dancing (Figure 4), and even a polymer of NanoPutians (Figure 5).

Fig 4 NanoPutian Couple

Fog 5 NanoPutian polymer

NanoPutians aren’t actually the first example of human-shaped molecule. For example, the molecule shown in Figure 6 has appeared as a joke in a journal published on April Fool’s Day. The molecule shown in Figure 7 has been introduced once as Buddha molecule. Nevertheless, NanoPutians were probably the first case where human-shaped molecules were synthesized systematically(?) to be published as a full paper.

Fig 6 human-shaped molecule Fig 7 molecular Buddha

The Role of NanoPutians
Besides being human-shaped, the NanoPutian molecules have neither notable properties nor potential usefulness for future. The synthesis is also too straightforward to make any significant methodological contribution to chemical science.
Then how did this research get funded and get to be published on Journal of Organic Chemistry? It turns out that the synthesis was a part of the chemistry education program at Rice University aimed at introducing nanotechnology to young students. In fact, it has also been on the cover page of Journal of Chemical Education too. It’s funny though, to imagine the faces of the journal editors when they first read the paper.
But come to think of it, molecules like dodecahedrane and kekulene might not be so different in terms of not having much to appeal other than their structural beauty. Even “total synthesis of biologically active natural products”, the most respected subfield of organic chemistry, has been criticized on its meaning recently. In a way, the NanoPutian research seems to me as a voice saying “synthetic targets should be selected more freely” and almost as an antithesis against the state of organic chemistry today.

Anyway, this paper was introduced by general media and was also one of the topics that received most feedbacks on my homepage. There were those who dismissed it as a meaningless play by chemists, but in terms of directing public interest toward organic chemistry wasn’t it a hundred times more effective than ordinary researches? I think it was an excellent work for the education of young chemists as well.
Professor Tour’s playful sense of molecular design can be seen in his research of NanoCars too, which I will introduce in a separate column. This is a wonderful work which can impress both serious scientists and general public.


nanohippie



nanorobot

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Biochemistry Department, Faculty of Agriculture, Cairo University, Giza, Egypt, 12613

*Corresponding author: Emad A. Shalaby Biochemistry Department, Faculty of Agriculture Cairo University, Giza, Egypt Tel: 002-02-01001203313 E-mail: drshalaby@staff.cu.edu.eg

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Synthesis of Tolvaptan

《Chinese Journal of Pharmaceuticals》 2011-02

Synthesis of Tolvaptan

pick up all this at

http://en.cnki.com.cn/Article_en/CJFDTotal-ZHOU201102007.htm

YANG Chuanwei~1,MU Shuai~2,LIU Ying~3,WANG Pingbao~3,LIU Dengke~(3*) 
(1.School of Pharmacy,Henan University,Kaifeng 475004;2.
School of Chemical Engineering and Technology,
 Tianjin University,Tianjin 300072;3.
Tianjin Institute of Pharmaceutical Research,Tianjin 300193)  

Tolvaptan,a selective nonpeptide arginine vasopressin V_2 receptor antagonist,was synthesized
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【Key Words】： tolvaptan arginine vasopressin V_2 receptor antagonist heart failure hyponatremia synthesis
【Fund】： 天津市科技计划项目(09ZCKFSH01300)
【CateGory Index】： R914

 Download(CAJ format)  Download(PDF format) 

CAJViewer7.0 supports all the CNKI file formats; AdobeReader only supports the PDF format.

	【Citations】

	Chinese Journal Full-text Database 2 Hits
	1 LI Fan1, HOU Xingpu2, LI Lin1, LU Tao1, DU Yumin1 (1. School of Pharmacy, Hebei Medical University, Shijiazhuang 050017; 2. Shijiazhuang  Pharma Group NBP Pharmaceutical Co., Ltd., Shijiazhuang 052160); Synthesis of Antiparkinsonian Agent Istradefylline[J];Chinese Journal of Pharmaceuticals;2010-04 2 YANG Miao~1,SHUAI Jun~2,LIU Mo~3,LIU Deng-ke~(3*),WANG Ping-bao~3 (1.Tianjin Medical University,Tianjin 300070;2.Tianjin University;Tianjin 300072;  3.Tianjin Institute of Pharmaceutical Research,Tianjin 300193); Synthesis of 7-Chloro-5-oxo-2,3,4,5-tetrahydro-1H-1-benzazepine[J]; Chinese Journal of Pharmaceuticals;2009-09

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	Chinese Journal Full-text Database 1 Hits
	1 XIONG Xiao-yi,CHEN An-qun,HE Yong-mei(Chongqing Unis Chemical Co.,Ltd.,Chongqing 402161,China);Analysis of Cyanoacetic Acid Content by HPLC[J];Guangzhou Chemical Industry;2010-12

Direct synthesis of hydrogen peroxide in water in a continuous trickle bed reactor optimized to maximize productivity

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DOI: 10.1039/C3GC40811F, Paper

Pierdomenico Biasi,*^a   Juan García-Serna,*^b   Alice Bittante^a and  Tapio Salmi^a

*

Corresponding authors

^a

Department of Chemical Engineering, Åbo Akademi University, Turku/Åbo, Finland
E-mail: bpierdom@abo.fi ;
Fax: +358 2 215 4479 ;
Tel: +358 2 215 4555

^b

Department of Chemical Engineering and Environmental Technology, University of Valladolid, Valladolid, Spain
E-mail: jgserna@iq.uva.es

Hydrogen peroxide direct synthesis was studied in continuous mode over a 5% wt Pd/C commercial catalyst in a Trickle Bed Reactor.

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*

Corresponding authors

^a

Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore 138669, Singapore
E-mail: ygzhang@ibn.a-star.edu.sg ;
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* Corresponding authors

^a

Department of Chemistry, The Pennsylvania State University, University Park, USA 
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COLUMN CHROMATOGRAPHY

A chemist in the 1950s using column chromatography. The Erlenmeyer receptacles are on the floor.

Column chromatography in chemistry is a method used to purify individual chemical compounds from mixtures of compounds. It is often used for preparative applications on scales from micrograms up to kilograms. The main advantage of column chromatography is the relatively low cost and disposability of the stationary phase used in the process. The latter prevents cross-contamination and stationary phase degradation due to recycling.

The classical preparative chromatography column, is a glass tube with a diameter from 5 mm to 50 mm and a height of 5 cm to 1 m with a tap and some kind of a filter (a glass frit or glass wool plug – to prevent the loss of the stationary phase) at the bottom. Two methods are generally used to prepare a column: the dry method, and the wet method.

• For the dry method, the column is first filled with dry stationary phase powder, followed by the addition of mobile phase, which is flushed through the column until it is completely wet, and from this point is never allowed to run dry.
• For the wet method, a slurry is prepared of the eluent with the stationary phase powder and then carefully poured into the column. Care must be taken to avoid air bubbles. A solution of the organic material is pipetted on top of the stationary phase. This layer is usually topped with a small layer of sand or with cotton or glass wool to protect the shape of the organic layer from the velocity of newly added eluent. Eluent is slowly passed through the column to advance the organic material. Often a spherical eluent reservoir or an eluent-filled and stoppered separating funnel is put on top of the column.

The individual components are retained by the stationary phase differently and separate from each other while they are running at different speeds through the column with the eluent. At the end of the column they elute one at a time. During the entire chromatography process the eluent is collected in a series of fractions. Fractions can be collected automatically by means of fraction collectors. The productivity of chromatography can be increased by running several columns at a time. In this case multi stream collectors are used. The composition of the eluent flow can be monitored and each fraction is analyzed for dissolved compounds, e.g. by analytical chromatography, UV absorption, or fluorescence. Colored compounds (or fluorescent compounds with the aid of an UV lamp) can be seen through the glass wall as moving bands.

Overview

Stationary phase

The stationary phase or adsorbent in column chromatography is a solid. The most common stationary phase for column chromatography is silica gel, followed by alumina. Cellulosepowder has often been used in the past. Also possible are ion exchange chromatography, reversed-phase chromatography(RP), affinity chromatography or expanded bed adsorption(EBA). The stationary phases are usually finely ground powders or gels and/or are microporous for an increased surface, though in EBA a fluidized bed is used. There is an important ratio between the stationary phase weight and the dry weight of the analyte mixture that can be applied onto the column. For silica column chromatography, this ratio lies within 20:1 to 100:1, depending on how close to each other the analyte components are being eluted.

Mobile phase (eluent)

The mobile phase or eluent is either a pure solvent or a mixture of different solvents. It is chosen so that the retention factor value of the compound of interest is roughly around 0.2 - 0.3 in order to minimize the time and the amount of eluent to run the chromatography. The eluent has also been chosen so that the different compounds can be separated effectively. The eluent is optimized in small scale pretests, often using thin layer chromatography (TLC) with the same stationary phase.

There is an optimum flow rate for each particular separation. A faster flow rate of the eluent minimizes the time required to run a column and thereby minimizes diffusion, resulting in a better separation. However, the maximum flow rate is limited because a finite time is required for analyte to equilibrate between stationary phase and mobile phase, see Van Deemter's equation. A simple laboratory column runs by gravity flow. The flow rate of such a column can be increased by extending the fresh eluent filled column above the top of the stationary phase or decreased by the tap controls. Faster flow rates can be achieved by using a pump or by using compressed gas (e.g. air,nitrogen, or argon) to push the solvent through the column (flash column chromatography).

The particle size of the stationary phase is generally finer in flash column chromatography than in gravity column chromatography. For example, one of the most widely used silica gel grades in the former technique is mesh 230 – 400 (40 – 63 µm), while the latter technique typically requires mesh 70 – 230 (63 – 200 µm) silica gel.

A spreadsheet that assists in the successful development of flash columns has been developed. The spreadsheet estimates the retention volume and band volume of analytes, the fraction numbers expected to contain each analyte, and the resolution between adjacent peaks. This information allows users to select optimal parameters for preparative-scale separations before the flash column itself is attempted.

An automated ion chromatography system.

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Typical set up for manual column chromatography

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CHECK THIS VIDEO

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