Chemical Science

Tuesday, 19 March 2013

Reimer-Tiemann Reaction

The Reimer-Tiemann reaction is an organic reaction used to convert a phenol to an o-hydroxy benzalde-hyde using chloroform, a base, and acid work-up.

The mechanism begins with abstraction of the proton from chloroform with the base to form a trichlorocarbanion which spontaneously loses a chloride ion to form a neutral dichlorocarbene.

The base also deprotonates the phenol reagent which then attacks the carbene.

A series of steps and a final acid work-up result in the o-hydroxy benzaldehyde product. For more click here.

Image Credit: chemistry.tutorvista.com

Credit: http://www.name-reaction.com/reimer-tiemann-reaction

Saturday, 16 March 2013

Amazing Water & Sound Experiment

Friday, 15 March 2013

18-Crown-6

18-Crown-6 is an organic compound with the formula [C₂H₄O]₆ and the IUPAC name of 1,4,7,10,13,16-hexaoxacyclooctadecane.
It is a white, hygroscopic crystalline solid with a low melting point.
Like other crown ethers, 18-crown-6 functions as a ligand for some metal cations with a particular affinity for potassium cations (binding constant in methanol: 10⁶M^-1).
The synthesis of the crown ethers led to the awarding of the Nobel Prize in Chemistry to Charles J. Pedersen.
Crown ethers are used in the laboratory as phase transfer catalysts.
In general however it is not widely used; cheaper and more versatile phase transfer catalysts are known.
In the presence of 18-crown-6, potassium permanganate dissolves in benzene giving the so-called "purple benzene", which can be used to oxidize diverse organic compounds.
More details are here.

Credit: http://en.wikipedia.org/wiki/18-Crown-6

Thursday, 14 March 2013

Foundations of Carbon-Based Life Leave Little Room for Error

Foundations of Carbon-Based Life Leave Little Room for Error

Life as we know it is based upon the elements of carbon and oxygen. Now a team of physicists, including one from North Carolina State University, is looking at the conditions necessary to the formation of those two elements in the universe. They’ve found that when it comes to supporting life, the universe leaves very little margin for error.

Light quark mass determines carbon and oxygen production and the viability of carbon-based life. Image credit: Dean Lee. Earth and Mercury images from NASA.

Albert Einstein Birthday

1879 - Albert Einstein was born. Einstein was a German physicist who was awarded the 1921 Nobel Prize in Physics for discovering the photoelectric effect. He is also known for his general theory of relativity which ties the forces of gravity, electricity and magnetism together.

For more go through here.

Wednesday, 13 March 2013

Organometallic Compounds

Compounds that contain a metal-carbon bond, R-M, are known as "organometallic" compounds.

Organometallic compounds of Li, Mg (Grignard reagents) are amongst some of the most important organic reagents.

Many other metals have been utilised, for example Na, Cu and Zn.

Organometallic compounds provide a source of nucleophilic carbon atoms which can react with electrophilic carbon to form a new carbon-carbon bond. This is very important for the synthesis of complex molecules from simple starting materials.

To rationalise the general reactivity of organometallics it is convenient to view them as ionic, so R-M = R-M+

The most important reactions is this chapter are the reactions of organolithiums, RLi, and Grignard reagents, RMgX, with the carbonyl groups in aldehydes, ketones and esters to give alcohols. However, we will also look at some useful reactions involving Cu, Zn and Hg (mercury).

For more details click here.

Credit: Dr. Ian Hunt, Department of Chemistry, University of Calgary

Ultra-High-Speed Optical Communications Link Sets New Power Efficiency Record

WASHINGTON, March 12, 2013—Next week, leaders from telecom, datacom and computing will convene for the Optical Fiber Communication Conference and Exposition/National Fiber Optic Engineers Conference (OFC/NFOEC)—the premier optical communications event where experts from industry and academia share their results, experiences, and insights on the future of hot topic areas such as cloud and datacenter networking, software-defined networks, photonic integration and more. More than 12,000 attendees and an exhibit with 550 companies are expected. For more details click here.

Optical link test chips, including transmitter (TX) circuits, laser diodes, photo diode, and receiver (RX) circuits. (Credit: Image courtesy IBM)

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Do not get over excited over happiness and do not get over depressed over sorrow.

Do not get over bonded with anyone and anybody because it can lead to problems and sorrow.

Never think that my duty is the topmost or lowermost. Every duty is respectful. The responsibility undertaken or given as per the position is the noblest duty.

Elevate yourselves, family, society and nation and never denigrate yourselves, family, society and nation.

We are our own closest relatives and if not properly utilised we will become our closest enemies.

There are possibilities of success and failure in any endeavour. One cannot assure success always.

Death is inevitable for everyone in this world. In any endeavour at the maximum an individual may die.

People may say good and also they may say bad. Approach them with stabilised mind.

Take anything after scientifically, logically and rationally analysing them.

Perform your duty, responsibility and accept the privileges eligible for you.

First change ourselves and then try to change others.

We are all instruments /tools in the hands of the nature for performing the duty. So do not think that I am doing the duty. Think that I am an instrument to do the duty.

Results of action may not be sweet always. Accept what ever may be the result.

Follow the path of great scholars who guided the world. Listen their messages.

Results and rewards will come and go but stick to your duty with devotion, dedication and sincerity.

Subhashitham

उद्यमेनैव सिध्यन्ति कार्याणि न मनोरथै: ।
न हि सुप्तस्य सिंहस्य प्रविशन्ति मुखे मृगा: ॥

अयं निज: परो वेति गणना लघुचेतसाम् ।
उदारचरितानां तु वसुधैव कुटुम्बकम् ॥

न कश्चिदपि जानाति
किं कस्य श्वो भविष्यति ।
अतः श्वः करणीयानि
कुर्यादद्धैव वुद्धिमान् ॥

आचार्यात् पादमादते पादं शिष्यः स्वमेधया ।
पादं सब्रह्मचारिभ्यः पादं कालक्रमेण च ॥

उपकारिषु यः साधुः सधुत्वे तस्य को गुणः ।
अपकारिषु यः साधुः स साधुरिति कीर्तितः ॥

च्छायामन्यस्य कुर्वन्ति तिष्ठन्ति स्वयमातपे ।
फलान्यापि परार्थाय वृक्षाः सत्पुरुषाः इव ॥

जलबिन्दुनिपातेन क्रमशः पूर्यते घटः ।
स हेतुः सर्वविद्यानां धर्मस्य च धनस्य च ॥

अग्निशेषमृणशेषं शत्रुशेषं तथैव च |
पुन: पुन: प्रवर्धेत तस्माच्शेषं न कारयेत् ||

पृथिव्यां त्रीणि रत्नानि जलमन्नं सुभाषितम् |
मूढै: पाषाणखण्डेषु रत्नसंज्ञा प्रदीयते ||

नाभिषेको न संस्कार: सिंहस्य क्रियते मृगैः |
विक्रमार्जितराज्यस्य स्वयमेव मृगेंद्रता ||

स्वभावो नोपदेशेन शक्यते कर्तुमन्यथा ।
सुतप्तमपि पानीयं पुनर्गच्छति शीतताम् ॥

यस्मिन् जीवति जीवन्ति बहवः स तु जीवति ।
काकोपि किं न कुरुते चञ्च्वा स्वोदरपूर्णम् ॥

दनेन तुल्यो विधिरास्ति नान्यो
लोभोच नान्योस्ति रिपुः पृथिव्या ।
विभूषणं शीलसमं च नान्यत्
सन्तोषतुल्यं धनमस्ति नान्यत् ॥

संरोहति अग्निना दग्धं वनं परशुना हतं ।
वाचा दुरुक्तं बीभत्सं न संरोहति वाक् क्षतम् ॥

अहो दुर्जनसंसर्गात् मानहानिः पदे पदे ।
पावको लोहसंगेन मुद्रगरैरभिताद्यते ॥

द्वौ अम्भसि निवेष्टव्यौ गले बद्ध्वा दृढां शिलाम् । धनवन्तम् अदातारम् दरिद्रं च अतपस्विनम् ॥

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