Chemistry 130 course documents archive

ACD/ILab (ACD Interactive Lab) Cheatsheet

URL: http://www2.acdlabs.com/ilab/

ACD/ILab is a new universal Web-based gateway to various chemical information resources, property prediction programs and chemical databases. Features available through ILab:

Chemical Naming Predicted Values
CAS Index Name HNMR Spectrum vapor pressure
IUPAC Name 13CNMR Spectrum enthalpy of vaporization
pKa aqueous solubility
LogP bioconcentration factor
boiling point adsorption coefficient
molar refractivity/volume parachor
refractive index surface tension
density dielectric constant
polarizability LogD

How to use ILab: First access the website. Log in. Load in a structure by either drawing one using ILab’s ChemSketch or importing a previously drawn .MOL file. Then select the property that you want displayed (e.g. HNMR).

To access ACD’s Interactive Lab:

  • point web browser to http://www2.acdlabs.com/ilab/
  • click on “Enter as SL User” in the left column
  • select “No profile” as the Login mode
  • click on “Enter as SL User” (under the Login mode choices)

A “How to Use ILAB” window appears. To open the structure drawing applet, click on “Structure” on the top bar. To load in a structure, click on the diskette icon.

To draw a structure, use ChemSketch.

ChemSketch screenshot
ChemSketch 2.5 structure drawing editor.

Top Buttons (from left): Clear, Undo, Redo, Bond Type (Normal, Up Stereo, Down Stereo), Delete, Move, Charge Plus, Charge Minus, Template, Zoom Out, Zoom In, Clean

Side Buttons (from top): Clear, Table of Elements, Common Elements (C, H, N, O, P, S, Cl)

To draw a carbon skeleton, shortcuts are available through the “templates” button.

Template screenshot

Click to select the template. Common functional groups will be found under “Groups”. To load a structure into ChemSketch, click on the structure until the template window disappears. Back in ChemSketch, click on the workplace window to paste your selected template into the editor window.

To change atom values, click on the appropriate element button on the left or click on the “table of elements” button above “C” to select an element, and then click on the node in the ChemSketch window that you want to change.

To change a bond value (single, double, or triple) click on the already existing bond. The bond value will cycle through from single to double to triple. Stop clicking when the bond value you want is reached.

Once your structure is drawn in the workplace window, you can use the “Clean” button (top row, far right) to adjust the angles and bond lengths of your drawing.

To import a .MOL structure, click on “Open MOL file” (top link in left column). Click on “Browse”. When the “File Upload” window appears, be sure “All Files” is selected in the “Files of Type” bottom window. Select the .MOL file to be imported. Click “Open” and you will return to the “Open MOL file” window. The pathname to your structure will appear in the MOL File dialog box. Click on “Load Structure”.

To display a property, first the structure must be drawn in the “Structure Drawing” editor or imported through the “Open MOL File” window. Then click on the property of interest, listed on the left column of the ILab window. When an explanatory window for the property appears, click on “Calculate” (or equivalent, i.e. “Get IUPAC name”). It may be necessary to move ChemSketch out of the way by clicking on the top bar of the structure drawing window, holding down the mouse button, and moving the window.

About HNMR

ACD/HNMR 2.5 calculates proton NMR spectra under any basic frequency using as a reference an internal data base of over 180,000 experimental chemical shifts and 25,000 coupling constants for 45,000 structures. Each chemical shift value is pre-assigned to the specific structural fragment. Each coupling constant is pre-assigned to a pair of structural fragments and the connecting fragmental skeleton. The internal data base of pre-assigned shifts and coupling constants has been generated from 48,000 experimental spectra. Java applets are used to visualize spectral plots with exact line numbers, intensities, locations and assignments.

The most accurate spectra are obtained for non-polar non-aromatic solvents. ACD/HNMR takes into account second order interactions (strong coupling effects) and long-range coupling constants, emulates double resonance and plots integral curves. It also allows you to calculate exact spectra for any strongly coupled system with up to eight magnetically non-equivalent nuclei (spin 1/2) or more if some nuclei are magnetically equivalent. ACD/HNMR emulates experimental conditions and allows you to specify spectrometer frequency and line widths. Only non-organometallic structures with up to 255 heavy atoms can be processed.

HNMR spectrum screenshot
HNMR Spectrum: Benzamide

Top Buttons (from left): Float, Zoom In, Zoom Out, Show Chemical Shifts, Show Intensities, Show Group Numbers, Print, Show, Show Discrete Lines, Show Realistic Lines, Scale in PPM, Scale in Hz, Full Spectrum, Full Scale, Show Integral Curve

For greater detail of the spectrum, click on the “Zoom In” button (top left “+”). A colored vertical line will appear in the window. Click, hold, and drag across areas on which to zoom in. Release the mouse button.

To print spectra, click on the printer icon. An image of the current java window will appear as a new web browser page. Sometimes, the image takes a few minutes to load onto the page.

To exit ILab, click on the “Exit ACD/ILAB” link (bottom of left column). You may have to move some of the results windows out of the way to see the link. To move the windows, use the mouse to click and hold on the top bar of the window and then drag the window out of the way. When you exit ILab, your results windows will all disappear.