Valence Calculations

Introduction

The Valence Calculator has 3 functionality:

• Set the appropiate amount of implicit H
• Set the charge
• Calculate if there is valence error
• Calculate if there is "impossible bond" error

The functionality of the Valence Calculator is focused mainly on the organic compounds, although the inorganic compounds not containing metallic atoms are also supported.

Molecules

1st Group

Hydrogen

• Default: H⁺
• Bonds: 1 bond is accepted

Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Caesium (Cs), Francium (Fr)

• Neutral atoms:
  • Default: Li, Na, K, Rb, Cs, Fr respectively.
• Ions:
  • Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺, Fr⁺ are accepted

2nd Group

• Neutral atoms:
  • Default: Be, Mg, Ca, Sr, Ba, Ra respectively.
• Ions:
  • Be²⁺, Mg²⁺, Ca²⁺, Ca²⁺, Sr²⁺, Ba²⁺ Ra²⁺are accepted

13th Group

Boron

• Placing a single Boron atom to the canvas results BH₃
• Neutral atoms are extended with as many implicit Hydrogens as necessary to have three bonds around them.
• Four bonds are possible: then the boron atom has one negative charge.
• Boron may form aromatic bonds as well.

Aluminium (Al), Gallium (Ga), Indium (In), Thallium (Th)

• Neutral atoms:
  • Default: Al, Ga, In, Th respectively.
• Ions:
  • Al⁺, Ga⁺, In⁺, Rb⁺, Al³⁺, Ga³⁺, In³⁺, Rb³⁺ are accepted.

14th Group

Carbon (C), Silicon (Si), Germanium (Ge)

• Neutral atoms:
  • Default: CH₄, SiH₄, GeH₄ respectively.
  • Bonds: Implicit Hydrogens are added to have 4 four bonds. 5 or more bonds are forbidden.
• Charged atoms in a molecule:
  • Every added charge on these atoms (no matter it is positive or negative) decreases by one the number of possible bonds. Maximum charge accepted is ±4.
• Radical:
  • Every added radical on these atoms decreases by one the number of bonds.

Aromatic Systems

General rules for aromatic compounds (in order of priority):

• Atoms with aromatic bonds and four or more ligands must have valence error.
• Carbon (C) atoms can add one electron to the aromatic system.
• Nitrogen (N) and Phophorus (P) can add one (having two ligands) or two (having three ligands) electrons to the aromatic system.
• Oxygen (O) and Sulfur (S) can add two electrons to the aromatic system.
• Boron (B) can add zero (having three ligands) or one (having two ligands) electron to the aromatic system.
• Charged atoms:
  • C⁺ must act like B
  • C^- must act like N
  • N^- must act like O
  • N⁺ must act like C
  • P^- must act like S
  • P⁺ must act like C
  • O⁺ must act like N
  • O^- must act like F hence it should have valence error
  • S⁺ must act like P
  • S^- must act like Cl hence it should have valence error
  • B⁺ must act like Be hence it should have valence error
  • B^- must act like C

• Given the form X=Y, where X is member of an aromatic ring while Y is not, e.g. C=O, C=N, C=S, C=P, N=O and P=O. Non ring double bond has so-called "single bond charge separated" mesomer form. Then the non-ring hetero atom, Y, gets negative charge and the ring member atom, X, gets positive and therefore they act as charged atoms described above.

• Ambiguous (in implicit H) aromatic ring cases:

  • Explore the system of aromatic rings.
  • Add the fixedly given electrons (e.g non charged C, S ,O adds one electron; N with 3 ligands adds two electrons).
  • Add the ambiguous cases to get the maximum and minimum number of aromatic electrons.
  • Check the Hückel rule.
  • A group consist of atoms adding one electron to the aromatic system must contain even number of atoms.
  • Fulfill the Hückel rule in such a way to approach the case when all ring member add one electron to the aromatic ring system.

Tin (Sn)

• Neutral atoms:
  • Default: Sn
  • Bonds: Implicit Hydrogens are added to have 4 four bonds (if Tin has at least 1 bond). 5 or more bonds are forbidden.
• Charged atoms in a molecule:
  • Every added charge (no matter it is positive or negative) decreases by one the number of possible bonds. Maximum charge accepted is ±4.
• Ions:
  • Sn²⁺ and Sn⁴⁺ are accepted.

Lead (Pb)

• Neutral atoms:
  • Default: Pb
  • Bonds:
    • Implicit Hydrogens are added to have 4 four bonds (if Lead has at least 1 bond).
    • 5 or 6 more bonds are accepted.
    • More than 6 bonds are forbidden.
• Charged atoms in a molecule:
  • Every added charge (no matter it is positive or negative) decreases by one the number of possible bonds. Maximum charge accepted is ±4.
• Ions:
  • Pb²⁺ and Pb⁴⁺ are accepted.

15th Group

Nitrogen (N)

• Neutral atoms:
  • Default: NH₃
  • Bonds:
    • Implicit Hydrogens are added to have 3 four bonds (if Nitrogen has at least 1 bond).
    • More than 3 bonds are forbidden.
    • Hogy lesz a 4 ligandos N charge beallitas?
      Nitrogen 5 kotessel?
• Charged atoms in a molecule:
  • Positive charge: One positive charge if N has four ligands is accepted.
  • Negative charge: Every added negative charge decreases by one the number of possible bonds. Maximum charge accepted is -3.
• Radical:
  • Every added radical on these atoms decreases by one the number of bonds. Maximum three added radical is allowed.

Phosphorus (P), Arsenic (As), Antimony (Sb)

• Neutral atoms:
  • Default: PH₃, AsH₃, SbH₃
  • Bonds:
    • 1 bond: 2 implicit Hydrogens are added.
    • 2 bond: 1 implicit Hydrogen is added.
    • 3 bond: 0 implicit Hydrogen is added.
    • 4 bond: 1 implicit Hydrogen is added.
    • 5 bond: 0 implicit Hydrogen is added.
    • More than 5 bonds are forbidden
• Charged atoms in a molecule:
  • Positive charge:
    • 1+: 4 bonds are necessary (including implicit Hydrogens).
    • 2+: 1 bond is necessary (including implicit Hydrogens).
    • 3+: 0 bond is allowed.
    • 4+: 1 bond is necessary (including implicit Hydrogens)
    • 5+: 0 bond is allowed.
    • 6+ or more: not allowed
  • Negative charge: Every added negative charge decreases by one the number of possible bonds. Maximum charge accepted is -3.
• Radical:
  • Every added radical on these atoms decreases by one the number of bonds. Maximum three added radical is allowed.

Bismuth (Bi)

16th Group

Oxygen (O)

• Neutral atoms:
  • Default: H₂O
  • Bonds:
    • Implicit Hydrogens are added to have 2 four bonds (if Oxygen has at least 1 bond).
    • More than 2 bonds are forbidden
• Charged atoms in a molecule:
  • Positive charge: One positive charge if O has three ligands is accepted.
  • Negative charge: One or two the negative charge is accepted, with one or zero ligands, respectively.
• Radical:
  • Every added radical on these atoms decreases by one the number of bonds. Maximum two added radical is allowed.

Sulfur (S), Selenium (Se), Tellurium (Te), Polonium (Po)

• Neutral atoms:
  • Default: H₂S, H₂Se, H₂Te, H₂Po
  • Bonds:
    • 1 bond: 1 implicit Hydrogen is added
    • 2 bond: 0 implicit Hydrogen is added
    • 3 bond: valence error on S/Se/Te/Po atom
    • 4 bond: 0 implicit Hydrogen is added
    • 5 bond: 1 implicit Hydrogen is added
    • 6 bond: 0 implicit Hydrogen is added
    • More than 6 bonds are forbidden
• Charged atoms in a molecule:
  • Ez most rossz!!!
  • Positive charge:
    • 1+: 1, 3 or 5 bonds are necessary (including implicit Hydrogens).
    • 2+: 0 or 4 bonds are necessary (including implicit Hydrogens).
    • 3+: 1 or 3 bonds are necessary (including implicit Hydrogens).
    • 4+: 0 or 2 bonds are necessary (including implicit Hydrogens).
    • 5+: 1 bond is necessary (including implicit Hydrogens).
    • 6+: 0 bond is allowed.
    • 7+ or more: not allowed.
  • Negative charge: One or two the negative charge is accepted, with one or zero ligands, respectively.
• Radical:
  • Every added radical on these atoms decreases by one the number of bonds. Maximum 2 added radical is allowed.

17th Group

18th Group

Superatom S-Groups

Query Structures