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Experimental data for CH2I2 (Diiodomethane)

22 02 02 11 45
Other names
methylene iodide; Methylene diiodide;
INChI INChIKey SMILES IUPAC name
InChI=1S/CH2I2/c2-1-3/h1H2 NZZFYRREKKOMAT-UHFFFAOYSA-N ICI
State Conformation
1A1 C2V
Enthalpy of formation (Hfg), Entropy, Integrated heat capacity (0 K to 298.15 K) (HH), Heat Capacity (Cp)
Property Value Uncertainty units Reference Comment
Hfg(298.15K) enthalpy of formation 118.00 4.20 kJ mol-1 webbook
Hfg(0K) enthalpy of formation   4.20 kJ mol-1 webbook
Information can also be found for this species in the NIST Chemistry Webbook
Vibrational levels (cm-1) vibrations
Mode Number Symmetry Frequency Intensity Comment Description
Fundamental(cm-1) Harmonic(cm-1) Reference (km mol-1) unc. Reference
1 A1 2986   1975For:185-193       CH2 s-stretch
2 A1 1422           CH2 scissors
3 A1 704           CI2 s-str
4 A1 285           CI2 scissors
5 A2 1155           CH2 twist
6 B1 3048           CH2 a-stretch
7 B1 896           CH2 rock
8 B2 1263           CH2 wag
9 B2 738           CI2 a-str

vibrational zero-point energy: 6248.5 cm-1 (from fundamental vibrations)
Calculated vibrational frequencies for CH2I2 (Diiodomethane).
Gas-phase IR spectra can be found in the NIST Chemistry Webbook here.
Rotational Constants (cm-1) rotational constants
See section I.F.4 to change rotational constant units
A B C reference comment
0.73499 0.02070 0.02021 1996Kis/Psz:1778-1785

Calculated rotational constants for CH2I2 (Diiodomethane).
Product of moments of inertia moments of inertia
1.558193E+07amu3Å6   7.1349234912876E-113gm3 cm6
Geometric Data
picture of Diiodomethane

Point Group C2v


Internal coordinates
distances (r) in Å, angles (a) in degrees, dihedrals (d) in degrees
Description Value unc. Connectivity Reference Comment
Atom 1 Atom 2 Atom 3 Atom 4
rCI 2.135 0.002 1 2 1998Kis/Psz:283-290
aICI 113.9 0.3 2 1 3 1998Kis/Psz:283-290
rCH 1.066 0.015 1 4 1998Kis/Psz:283-290 r0
aHCH 111.6 2.4 4 1 5 1998Kis/Psz:283-290

Cartesians
Atom x (Å) y (Å) z (Å)
C1 0.0000 0.0000 1.0721
I2 0.0000 1.7895 -0.0922
I3 0.0000 -1.7895 -0.0922
H4 -0.8817 0.0000 1.6713
H5 0.8817 0.0000 1.6713

Atom - Atom Distances bond lengths
Distances in Å
  C1 I2 I3 H4 H5
C1   2.13502.13501.06601.0660
I2 2.1350   3.57912.66272.6627
I3 2.13503.5791   2.66272.6627
H4 1.06602.66272.6627   1.7633
H5 1.06602.66272.66271.7633  

Calculated geometries for CH2I2 (Diiodomethane).

Experimental Bond Angles (degrees) from cartesians bond angles

atom1 atom2 atom3 angle         atom1 atom2 atom3 angle
I2 C1 I3 113.900 I2 C1 H4 107.851
I2 C1 H5 107.851 I3 C1 H4 107.851
I3 C1 H5 107.851 H4 C1 H5 111.600

Bond descriptions


Examples: C-C single bond, C=C, double bond, C#C triple bond, C:C aromatic bond
Bond Type Count
H-C 2
C-I 2

Connectivity
Atom 1 Atom 2
C1 I2
C1 I3
C1 H4
C1 H5
Electronic energy levels (cm-1)
Energy (cm-1) Degeneracy reference description
0 1   1A1

Ionization Energies (eV)
Ionization Energy I.E. unc. vertical I.E. v.I.E. unc. reference
9.460 0.020     webbook
Dipole, Quadrupole and Polarizability
Electric dipole moment dipole
State Config State description Conf description Exp. min. Dipole (Debye) Reference comment Point Group Components
x y z total dipole quadrupole
1 1 1A1 C2v True           C2v 1 2
Experimental dipole measurement abbreviations: MW microwave; DT Dielectric with Temperature variation; DR Indirect (usually an upper limit); MB Molecular beam
Calculated electric dipole moments for CH2I2 (Diiodomethane).
Electric quadrupole moment quadrupole
State Config State description Conf description Exp. min. Quadrupole (D Å) Reference comment Point Group Components
xx yy zz dipole quadrupole
1 1 1A1 C2v True       C2v 1 2

Calculated electric quadrupole moments for CH2I2 (Diiodomethane).

References
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squib reference DOI
1975For:185-193 TA Ford "Infrared and Raman Spectra and Vibrational Assignments of Diiodomethane and Its Deuterated Analogs" J. Mol. Spect. 58, 185-193 (1975) 10.1016/0022-2852(75)90104-6
1996Kis/Psz:1778-1785 Z Kisiel, L Pszczólkowski, W Caminati, and PG Favero "First assignment of the rotational spectrum of a molecule containing two iodine nuclei: Spectroscopic constants and structure of CH2I2" J. Chem. Phys. 105, 1778 (1996) 10.1063/1.472053
1998Kis/Psz:283-290 Z Kisiel, L Pszczołkowski, LB Favero, W Caminati "Rotational Spectrum of CD2I2: An Isotopomer of the First Molecule Containing Two Iodine Nuclei Investigatedby Microwave Spectroscopy" J. MOL. SPECT. 189,283 – 290 ( 1998 ) 10.1006/jmsp.1998.7556
webbook NIST Chemistry Webbook (http://webbook.nist.gov/chemistry) 10.18434/T4D303

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