Heavier group 13/15 multiple bond systems: Synthesis, Structure and Chemical Bond Activation

2022 ◽  
Author(s):  
Fabian Dankert ◽  
Christian Hering-Junghans
Keyword(s):  
Double Bond ◽  
Chemical Bond ◽  
Bond Activation ◽  
Multiple Bond ◽  
Multiple Bonds ◽  
Group 13

Heavier group 13/15 multiple bonds have been under investigation since the late 80s and to date, several examples have been published, which shows the obsoleteness of the so-called double bond...

Adding Up: Addition

Reactions ◽  
2011 ◽  
Author(s):  
Peter Atkins
Keyword(s):  
Double Bond ◽  
Negative Charge ◽  
Bromine Atom ◽  
Multiple Bond ◽  
Molecular Size ◽  
Multiple Bonds ◽  
Dense Cloud ◽  
Starting Point ◽  
Multiply Bonded ◽  
A Chain

Adding up, or more formally ‘addition’, is just what it says: it is the attachment of atoms to a sensitive spot on a molecule. I need to stand back for a moment and explain what I mean by a ‘sensitive spot’. You already know (from Reaction 13) that some atoms are held to each other by an electron cloud (a ‘single bond’) and others by a doubly dense cloud (a ‘double bond’). There is a third type in which the atoms are held together by an even denser, triply dense cloud of electrons, forming a ‘triple bond’. Here I am concerned with the latter two types of bond, the so-called ‘multiple bonds’. These are the sensitive spots of organic molecules for it is quite easy to attack a multiple bond, rearrange the clouds, and attach other groups. For simplicity, I shall deal only with the more common type of multiply bonded molecule, one with a double bond. A double bond is a region rich in electrons, so you should suspect that any missile that will attack it will be an electrophile (a seeker-out of negative charge, of electron richness, Reaction 16). I shall consider a very simple case: the addition of bromine to cyclohexene, 1. As we have seen in Reaction 15, the presence of a bromine atom, Br, in a molecule is often the starting point for building on other groups of atoms, so this is an important reaction in a chain that might be used to construct something useful, such as a pharmaceutical. Bromine is a liquid composed of Br2 molecules. Cyclohexene is a liquid composed of hexagonal benzene-like molecules but with only one double bond in each molecule. Why I have chosen this slightly elaborate molecule rather than something simpler, such as ethylene (ethene, Reaction 13), will soon become clear. Let’s shrink together down to our normal molecular size and watch what happens as the bromine is poured into the cyclohexene. We already know from Reaction 16 that a bromine molecule has a nose for negative charge, so you should not be surprised to see one homing in on the electron-rich double bond of a nearby cyclohexene molecule.

Gradient-Enhanced Inverse-Detected NMR Techniquesfor Determination of 1H-15N Coupling Constants in 2,2-Dimethylpenta-3,4-dienal Derivatives

1997 ◽  
Vol 62 (11) ◽  
pp. 1747-1753 ◽  
Author(s):  
Radek Marek
Keyword(s):  
Double Bond ◽  
Chemical Shifts ◽  
Multiple Bond ◽  
Coupling Constants ◽  
Single Quantum ◽  
Nmr Techniques ◽  
Phase Sensitive ◽  
Heteronuclear Coupling

Determination of 15N chemical shifts and heteronuclear coupling constants of substituted 2,2-dimethylpenta-3,4-dienal hydrazones is presented. The chemical shifts were determined by gradient-enhanced inverse-detected NMR techniques and 1H-15N coupling constants were extracted from phase-sensitive gradient-enhanced single-quantum multiple bond correlation experiments. Stereospecific behaviour of the coupling constants 2J(1H,15N) and 1J(1H,13C) has been used to determine the configuration on a C=N double bond. The above-mentioned compounds exist predominantly as E isomers in deuteriochloroform.

Strukur und Reaktivität von Al2Cp*+ in der Gasphase. Ein experimenteller Beitrag zur Problematik der Aluminium-Aluminium- Doppelbindung / Structure and Reactivity of Al2Cp*+ in the Gas Phase. Experiments on the Problematic Nature of the Aluminum-Aluminum-Multiple Bond

2004 ◽  
Vol 59 (11-12) ◽  
pp. 1512-1518 ◽  
Author(s):  
K. Koch ◽  
H. Schnöckel
Keyword(s):  
Double Bond ◽  
Gas Phase ◽  
Quantum Chemical Calculations ◽  
Mass Spectrometer ◽  
Quantum Chemical ◽  
Multiple Bond ◽  
New Approach ◽  
Existence And Stability ◽  
Ft Icr

The cation Al2Cp*+ descending from the tetrahedral Al4Cp*4 Cluster after using LDI as ionisation method in an FT-ICR mass spectrometer reacts with Cl2 in the gas phase. The investigation of this reaction together with quantum chemical calculations gives a new approach to the question of existence and stability of an aluminum-aluminum double bond.

scholarly journals Femtosecond Infrared Studies of Chemical Bond Activation

1999 ◽  
Vol 19 (1-4) ◽  
pp. 253-262 ◽  
Author(s):  
M. C. Asplund ◽  
H. Yang ◽  
K. T. Kotz ◽  
S. E. Bromberg ◽  
M. J. Wilkens ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Chemical Bond ◽  
Bond Activation ◽  
Product Formation ◽  
Organometallic Complexes ◽  
Activation Time ◽  
Activation Reaction ◽  
Infrared Studies ◽  
Important Intermediate ◽  
Solvent Complex

The identification of the intermediates observed in bond activation reactions involving organometallic complexes on time scales from femtoseconds to milliseconds has been accomplished through the use of ultrafast infrared spectroscopy. C—H bond activation by the molecule Tp*Rh(CO)2 showed a final activation time of 200 ns in cyclic solvents, indicating a reaction barrier of 8.3 kcal/mol. An important intermediate is the partially dechelated η2-Tp*Rh(CO)(S) solvent complex, which was formed 200 ps after the initial photoexcitation. Si—H bond activation by CpM(CO)3 (M=Mn, Re) showed some product formation in less than 5 ps, indicating that the Si—H activation reaction is barrierless. The activated product was formed on several timescales, from picoseconds to nanoseconds, suggesting that there are different pathways for forming final product which are partitioned by the initial photoexcitation.

scholarly journals Advances in the development of complexes that contain a group 13 element chalcogen multiple bond

2016 ◽  
Vol 45 (23) ◽  
pp. 9385-9397 ◽  
Author(s):  
Daniel Franz ◽  
Shigeyoshi Inoue
Keyword(s):  
Multiple Bond ◽  
Group 13

The advances in the synthesis and isolation of complexes that contain a group 13 element chalcogen multiple bond are accounted for.

Azo-complexes of bis(cyclopentadienyl)-titanium and -vanadium; model systems for N–N multiple bond activation

1983 ◽  
pp. 1515-1521 ◽  
Author(s):  
Giovanni Fochi ◽  
Carlo Floriani ◽  
Jan C. J. Bart ◽  
Giovanni Giunchi
Keyword(s):  
Bond Activation ◽  
Multiple Bond ◽  
Model Systems

Copper-catalyzed, hypervalent iodine mediated CC bond activation of enaminones for the synthesis of α-keto amides

2016 ◽  
Vol 52 (6) ◽  
pp. 1270-1273 ◽  
Author(s):  
Jie-Ping Wan ◽  
Yunfang Lin ◽  
Xiaoji Cao ◽  
Yunyun Liu ◽  
Li Wei
Keyword(s):  
Double Bond ◽  
Bond Activation ◽  
Hypervalent Iodine ◽  
General Synthesis

An unprecedented approach toward the general synthesis of α-keto amides has been established by tailoring the CC double bond of enaminones in the presence of CuI and hypervalent iodine.

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