CE ÎNSEAMNĂ GEMINAL ÎN ENGLEZĂ?
geminala
În chimie, termenul geminal se referă la relația dintre doi atomi sau grupări funcționale care sunt atașate la același atom. Cuvântul vine de la gemenii latini ceea ce înseamnă "gemeni". Un diol geminal, de exemplu, este un diol atașat la același atom de carbon, ca în metanediol. Prefixul bijuterie poate fi, de asemenea, aplicat la un nume chimic pentru a desemna această relație, ca într-o gem-dibromură pentru "dibromid geminal". Conceptul este important în multe ramuri ale chimiei, incluzând sinteza și spectroscopia, deoarece grupurile funcționale atașate la același atom se comportă deseori diferit de atunci când sunt separate. Diolii gemeni, de exemplu, sunt ușor convertiți în cetone sau aldehide cu pierdere de apă. Următorul exemplu prezintă conversia unei ciclohexil metil cetone la o gem-diclorură printr-o reacție cu pentaclorură de fosfor. Această gem-diclorură poate fi apoi utilizată pentru a sintetiza o alchină. Termenul asemănător vicinal se referă la relația dintre două grupuri funcționale care sunt atașate la atomii adiacenți.
Definiția geminal în dicționarul Engleză
Definiția geminalului din dicționar este de, referitoare la sau având o pereche. O altă definiție a geminalului are două grupuri funcționale.
CĂRȚI ÎN ENGLEZĂ ÎN LEGĂTURĂ CU «GEMINAL»
Descoperă întrebuințarea
geminal în următoarea selecție bibliografică. Cărți în legătură cu
geminal și extrase din aceasta pentru a furniza contextul de întrebuințare al acestuia în literatura Engleză.
1
Basic 1H- and 13C-NMR Spectroscopy
The question of whether or not the formed norcaradiene structures 68 and 69 are
in equilibrium with their valence isomer, cycloheptatriene, can be easily
answered by measuring the geminal coupling constants between the bridge
methylene ...
2
Modern Physical Organic Chemistry
CH3 H Geminal repulsion Geminal repulsions do not lead to enhanced gauche
interactions Anti Gauche Figure 2.8 In tetramethylethane, geminal repulsions
between methyls cause expansion of the C-C-C angle, leading to enhanced
gauche ...
Eric V. Anslyn, Dennis A. Dougherty,
2006
HBr Addition of HX to Alkynes: Formation of Geminal Dihalides Because the TT
system of an alkyne closely resembles that of an alkene, addition of HX to triple
bonds seems likely to occur by a similar mechanism. Using knowledge of the ...
Marye Anne Fox, James K. Whitesell,
2004
4
Aspects of Strongly Orthogonal Singlet
Geminal Wave Functions
Feng Xu. as described in freshman general chemistry textbook. This intuitive
picture, when combined with the semi-empirical theory of hybridization of orbitals,
can predict and explain the geometry features of a large class of molecules.
5
Dianion Chemistry in Organic Synthesis
2.2 1,1-(C,C)-DIANIONS (GEMINAL DIANIONS) Several reviews have covered
the generation and reactions of dianions formed from stepwise deprotonations
from a sole methylene group.3'5'6 This process, leading to geminal ...
Charles M. Thompson,
1994
6
Introduction to Spectroscopy
H a ' Hb' If conformation is locked (no rotation) 1-Chloropropane Ha Hb CH3 Cl
CH2 CH2 CH3 c b a Cl As one can see, it is a frequent occurrence that one
needs to determine whether two groups attached to the same carbon (geminal
groups) ...
Donald Pavia, Gary Lampman, George Kriz,
2014
7
The Construction of Spin Eigenfunctions: An Exercise Book
The first f(N,S) geminal products are those whose path diagrams are identical to
the corresponding Serber branching diagrams, the remaining geminal functions
are ordered according to the last letter sequence. The proof will again be ...
8
Valency and Bonding: A Natural Bond Orbital Donor-Acceptor ...
3.78), geminal delocalization creates formal A+, C~ character on atoms that are
in close spatial proximity,111 with no compensating gain in covalent double-
bond character elsewhere. Hence, geminal delocalization corresponds to
general ...
Frank Weinhold, Clark R. Landis,
2005
This is referred to as geminal coupling (Figure 13.20). Geminal coupling
constants are generally small, on the order of 0 to 5 Hz. Because of the restricted
rotation about CIC bonds, the alkenyl (vinylic) H atoms of unsymmetrical alkenes
are not ...
William Brown, Brent Iverson, Eric Anslyn,
2013
10
Characterization and Chemical Modification of the Silica Surface
There is some discussion in literature, concerning the existence of geminal
hydroxyl groups. These groups were first proposed by Peri2 in 1968. Van
Cauwelaert3 stated that the free hydroxyl stretching vibration (3745 cm") consists
of 2 ...
E.F. Vansant, P. Van Der Voort, K.C. Vrancken,
1995
ȘTIRI NOI CARE INCLUD TERMENUL «GEMINAL»
Află ce ziare naționale și internaționale au scris despre și cum este întrebuințat termenul
geminal în contextul următoarelor știri.
Smell Receptors Sniff Out An Aldehyde In Its Hydrated Form
Now scientists have discovered a new aspect of this process: Some odorant receptors recognize an aldehyde via its hydrated geminal diol form ... «The Biological SCENE, Sep 14»
Diet, exercise and stress management may reverse aging on …
The study followed 35 participants five years after their initial entry into two separate studies: the GEMINAL study and UCSF MENS study. «CTV News, Sep 13»
Federal court issues prohibition order in respect of zoledronate …
... compounds containing a 5-membered, ring, which is connected to the geminal BP [bisphosphonate] carbon by a one-carbon linker (-CH2-). «Lexology, Mar 13»
Links for the Upstate Hasidic Weed Connection
He did research in the treatment of MS, Parkinson disease, Epilepsy, Tri-geminal Neuralgia and migraine headaches. He wrote a book on MS ... «Heeb Magazine, Iul 11»
How You Nurture Your Health Could Change Your Genetic Nature
These men were enrolled into a trial called GEMINAL, developed and implemented by my friend, Dr. Dean Ornish, and his colleagues at the ... «Huffington Post, Aug 10»
Hybrid organic–inorganic rotaxanes and molecular shuttles
The chirality is particularly apparent in the unequal magnetic effect exerted on each geminal proton in the methylene groups of the thread as ... «Nature.com, Mar 09»
Diet, Lifestyle Changes Effect at Genetic Level
He recently reported on the Gene Expression Modulation by Intervention with Nutrition and Lifestyle (GEMINAL) study. This study indicated that ... «Natural News.com, Aug 08»
Prostate cancer and lifestyle
In this case series, called the Gene Expression Modulation by Intervention with Nutrition and Lifestyle (GEMINAL), the researchers looked at the ... «NHS Choices, Iun 08»
Calcium is key for platinum drug delivery
Giovanni Natile at the University of Bari, Italy, and co-workers designed a novel platinum complex with geminal bisphosphonate ligands. «Chemistry World, Iul 07»