DE2748951A1 - Electronic calculator for chemical calculations - determines atomic and molecular wt. distributions and has keys for associated arithmetical processes - Google Patents

Abstract

An electronic calculator is designed for chemical applications. It has the four basic arithmetic function keys, keys for decimal numbers, decimal points, automatic percentage; storage and further calculations, a display, and electronic circuits connected to the keys, display, and store. It is designed to facilitate numeral constant input, and the calculation of molecular wts., molecular fragment wts., and wt. distributions of chemical elements and molecules. It has additional keys with symbols of chemical elements and functional groups for different molecular types whereby the operation of a key draws an appropriate wt. value from store.

Description

Electronic calculators for chemical purposes

The invention relates to an electronic computer for chemical purposes, in particular an electronic calculator.

There are now a number of different types of pocket calculators on the market, all more or less clearly intended to be the "traditional Slide rule "or the traditional electromechanical calculating machine. As a rule, these electronic computers combine the four basic arithmetic operations and - depending on the price range - other higher types of invoices. Devices in the upper price range offer special types of invoices and are therefore carried out by specialists (engineers, Physicists, mathematicians). In general, the trend is emerging that Electronic computers offered for specialists have a complicated construction and accordingly are expensive to manufacture.

According to the target group of buyers, the number of pieces is relative small, so that the manufacturing price of such a calculator is very high.

In the field of chemistry, especially organic chemistry, must often molecular weights (or more precisely: molecular masses) of chemical compounds calculated, fractions of the molecular weight given as well as percentage weight (or more precisely: mass) proportions of an element or a molecule in one Molecule can be calculated.

Such bills are mostly still "by hand" or executed in the interaction of "hand + electronic computer". However, both methods are relatively expensive, as the corresponding atomic and molecular weights from tables must be read and entered into such a computer. on the other hand however, molecular weights and percentages of elements or parts of molecules can also be used looked up directly in H. Gysel: "Percentage tables of organic compounds", 1962 will. Apart from that, compared to the price of such a reference book a standard pocket calculator is relatively high, so is the content of this The work is not exhaustive, so molecular weights or percentages, in particular of less common compounds and of newly-synthesized compounds, too can still be calculated mainly by hand.

In the field of mass spectroscopy, too, the mass of molecular fragments can be calculated exactly. The molecular mass has an accuracy of five digits absolutely necessary. A special table is usually used for this purpose (e.g. Henneberg and K. Casper, "Gross formulas from mass determinations", exclusive distribution VARIAN MAT GmbH, Bremen) and the exact mass of the molecule fragments look up laboriously.

The invention is therefore based on the object of providing a device create, with the one hand the tedious entering of number constants in a Computer canceled and on the other hand the calculation of molecular weights or molecular fragment weights as well as the weight fractions of a chemical element or a part of a molecule in a molecule with the help of an electronic computer will.

The invention is based on an electronic computer that controls the keys the four basic arithmetic operations, the decimal numbers, the comma, the automatic percentage, if necessary, buttons of memories and a display as well as those with these buttons, the display and any memories that may be present Has circuit. The electronic computer according to the invention is characterized in that that he also has buttons with symbols of chemical elements, functional groups, of different types of molecule parts and / or of molecules whose atomic or Molecular weights are entered as constants into the computer via a circuit and can be called up by pressing these keys for arithmetic operations and, if necessary appear on the display.

The functional group n is the parts (groups) of a To understand molecules that usually enter into a chemical reaction (e.g.

the amino, hydroxyl, carbonyl, carboxyl group, etc. Under different Molecular parts are non-functional parts of a molecule, but they are are often used to characterize molecules (e.g. methoxyl groups in the case of ethers, certain parts of the molecule that are split off in the mass spectrometer, for example such as C6H5, C7H7, HCN or similar in a preferred embodiment the electronic computer according to the invention has a keyboard in addition to its usual keyboard with symbols of chemical elements, via which by pressing the corresponding Key in the number of the atomic weight of the corresponding element in the calculation is introduced and possibly appears on the display and thus for a Arithmetic operation is available.

By pressing the key, one is preset in the circuit Constant released. A molecular weight calculated in this way, for example, can can be saved for further arithmetic operations.

In a further preferred embodiment of the invention Electronic computer is the keyboard with the symbols of the elements with the keyboard of decimals united. So that the atomic weight of the corresponding element and not, as usual, the decimal number is released, a special separation key has to be used must be activated before pressing the key with the two symbols decimal number / element.

One or more arithmetic operations are useful after pressing an element key, so that, for example, when calculating the Molecular weight of a compound pressing the addition key or the addition key and the multiplication key are unnecessary.

On the other hand, in addition to the keyboard with the different possibilities of chemical symbols the usual buttons with the symbols the four basic arithmetic operations, decimal numbers, the comma, an automatic percentage key, a delete key, a display that can contain eight digits, for example, and if applicable Memory buttons. The computer can be operated by battery, rechargeable battery or mains.

The atomic masses entered into the calculator as constants and used in the calculation process can be on a relative atomic mass of 12 based on C = 12; this basis then also applies accordingly to the calculated Values, e.g. B. a molecular weight or the percentage by weight of a Element. The values for the individual elements are in "International Union of Pure and Applied Chemistry ", Vol. 21 (1970), p. 91. Typically are Values with two digits after the decimal point are sufficient for chemical calculations.

A computer designed for mass spectroscopy points against it the numerical values of the isotopes, for example of Cl35 and Cl37. For this purpose 5 or 6-digit isotope masses are permanently entered into the computer.

In a special embodiment, the computer has the symbols the following elements: C, H, N, O, S Cl and P, making about 95% of all in the organic Chemistry bills are to be solved.

Optionally, as further elements, in particular F, Br, Na or K, to be included.

The invention is based on exemplary embodiments and the drawing explained.

Examples 1 to 4 Each of the pocket calculators shown in the drawing shows the symbols of the basic arithmetic operations +, -, x and: as well as the decimal numbers 0 to 9, the comma., The automatic percent and the delete key L.

Example 1 The computer shown in FIG. 1 also has the symbols the elements C, H, N, O, Na, Cl, S and P, which are stored as constants in the computer and appear on the display by pressing the key.

For the calculation of Nitrobenzene C 6H5NO2 the following keys are used one after the other to press: C x 6 + H x 5 + N x 1 + O x 2 = 16 operations are to be carried out, Example 2 The pocket calculator shown in FIG. 2 has, in addition to the in Example 1 given element symbols the symbol of fluorine F on.

In this calculator, an arithmetic operation, namely multiplying, automatically initiated after pressing an element key, so that the calculation of the nitrobenzene only 12 operation steps, namely the pressing of the keys C 6 + H 5 + N 1 + C 2 =, required.

Example 3 The computer shown in Figure 3 is in addition to the computer according to FIG. 2 with the element symbol Br, that is to say with a total of 10 element symbols.

This calculator automatically performs 2 arithmetic operations Press the element key directly (multiply) or indirectly (add) be initiated. The addition step is, however, activated by pressing the symbol = canceled.

For the calculation of the nitrobenzene there are only 9 operations, namely C 6 H 5 N 1 0 2 = to perform. Such a calculated molecular weight can stored and then subjected to further arithmetic operations, example 4 The computer shown in Figure 4 also has the symbols of the elements Ca H, N, O, Na, C1, S and P, which are stored as constants in the computer and by Press the button to appear on the display.

The calculator also has an "automatic clamp" that it allows you to set priorities for different calculation steps.

Claims (9)

Claims: Electronic computer that uses the keys of the 4 basic arithmetic operations, the decimal numbers, the comma, the automatic percentage, if necessary buttons of memories and / or from further arithmetic operations and a display as well as those with these keys, the display and any memories that may be present Having circuit, characterized in that it also has buttons with symbols chemical elements, functional groups, different molecular parts andjoder of molecules whose atomic or molecular weights as constants over a Circuit entered into the calculator and using these keys for Calculation processes can be called up and may appear on the display. 2. Calculator according to claim 1, characterized in that it has the keys with symbols of chemical elements. 3. Calculator according to claim 2, characterized in that it has the keys with the symbols of the elements C, H, N, O, Na, C1, S and P. 4. Computer according to one of claims 1 to 3, characterized in that that the keyboard with the symbols of the elements with the keyboard of the symbols of the Decimal numbers match and the effect of this keyboard in arithmetic operations can be controlled via a disconnect button. 5. Computer according to one of claims 1 to 4, characterized in that that the button with the symbol of an element, a functional group, of different Molecular parts and / or a molecule with several arithmetic operations, such as adding and multiply, circuit-wise g # k # ppelt is - 6. Calculator according to one of claims 1 to 5, characterized in that the button with the Symbol of an element, a functional group, of different parts of the molecule and / or a molecule with the arithmetic operation multiply in a circuit is coupled. 7. Computer according to one of claims 1 to 6, characterized in that that the constants as numbers with two decimal places in the calculator are entered. 8. Computer according to one of claims 1 to 6, characterized in that that the constants as numbers with at least five digits after the decimal point in the Calculator are entered. 9. Use of the computer according to one of claims 1 to 8 for the Calculation of molecular weights or percentages by weight of an element or a part of a molecule in a molecule.