Chapter 1: Structure and Bonding

Flashcards about Structure and Bonding in Organic Chemistry

Organic Chemistry is defined as __

The chemistry of compounds containing ‘Carbon’ element

The scope of organic chemistry includes __

Molecular structure: How e- forms bond, Reaction: transformation from one structure to another, Reaction mechanism: description of reaction pathway at an electronic level, Relationship between structure and reactivity

Valence electrons are __

outer shell electrons of an atom

The valence electrons are __

the electrons that participate in chemical bonding

Bonding is __

the joining of two atoms in a stable arrangement

Through bonding, __

atoms gain, lose, or share electrons to attain the electronic configuration of the noble gas closest to them in the periodic table

Ionic bonds __

result from the transfer of electrons from one element to another.

Covalent bonds __

result from the sharing of electrons between two nuclei.

An ionic bond generally occurs __

when elements on the far left side of the periodic table combine with elements on the far right side, ignoring noble gases

Covalent bonding

Occurs with elements like carbon in the middle of the table with elements that have similar electronegativity. They also occur between two of the same elements from the sides of the table

A covalent bond is __

a two-electron bond

Shared e- are also known as __

bonding e-

Unshared e- are also known as __

nonbonding (nonbonded) e-’ or ‘lone pairs’

Isomers are __

different molecules having the same molecular formula (different arrangement of atoms)

Resonance structures are __

not real. An individual resonance structure does not accurately represent the structure of a molecule or ion

Resonance structures are __

not in equilibrium with each other

Two isomers __

differ in the arrangement of both atoms and electrons, whereas resonance structures differ only in the arrangement of electrons

Major & minor contributor: __

A major contributor is a more stable form (more bonds and fewer charges)

Resonance structures are not real: __

The true structure is a resonance hybrid

__ resonance stabilized.

Electron pairs are delocalized, & e- delocalization adds stability

A curved arrow __

shows the movement of an e- pair

Calculating Degrees of Unsaturation __

gives the total number of rings and/or π bonds in a molecule

Condensed Structures: __

Carbon is tetravalent. All of the atoms are drawn in, but the two-electron bond lines are generally omitted

Skeletal Structures: __

Assume a carbon atom is located at the junction of any two lines or at the end of any line., Assume each carbon has enough hydrogens to make it tetravalent., Draw in all heteroatoms and the hydrogens directly bonded to them.

Valence Shell Electron Pair Repulsion (VSEPR) theory: __

Atoms or lone pair e- are as far away from each other as possible.

Sigma bond: __

cylindrically symmetrical

Electronegativity is __

a measure of an atom’s e- attracting ability in a bond

Nonpolar bond: __

e- are equally shared

Polar bond: __

e- are unequally shared

δ+ : __

electron deficient

δ- : __

electron rich

 : __

direction of polarity in a bond