How does plane-polarized light differ from ordinary light? Draw the structure of a chromium complex that rotates the plane of plane-polarized light.

Verified step by step guidance

Step 1: Understand the nature of ordinary light. Ordinary light consists of waves that vibrate in multiple planes perpendicular to the direction of propagation.

Step 2: Define plane-polarized light. Plane-polarized light is light that has been filtered so that its waves vibrate in only one plane.

Step 3: Recognize that certain substances can rotate the plane of plane-polarized light. This property is known as optical activity, and it is often observed in chiral molecules.

Step 4: Consider the structure of a chiral chromium complex. A common example is a tris(oxalato)chromate(III) complex, which can exist in enantiomeric forms that are mirror images of each other.

Step 5: Draw the structure of the chiral chromium complex. Represent the chromium ion at the center, coordinated to three oxalate ligands, ensuring the arrangement is non-superimposable on its mirror image to exhibit chirality.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Plane-Polarized Light

Plane-polarized light consists of waves that oscillate in a single plane, as opposed to ordinary light, which contains waves oscillating in multiple planes. This polarization can be achieved using a polarizing filter, which allows only light waves aligned with its axis to pass through. The unique properties of plane-polarized light are crucial in studying optical activity in substances.

Optical Activity

Optical activity refers to the ability of certain substances, particularly chiral compounds, to rotate the plane of plane-polarized light. This phenomenon occurs due to the asymmetrical arrangement of atoms in chiral molecules, which interact differently with light waves. The degree of rotation can be measured and is specific to the substance and its concentration, providing valuable information about its structure.

Chromium Complexes

Chromium complexes are coordination compounds where chromium is bonded to various ligands, which can influence their optical properties. Some chromium complexes exhibit optical activity due to their geometric arrangement and the presence of chiral ligands. Drawing the structure of such a complex involves representing the central chromium atom, its oxidation state, and the ligands attached, which can help visualize how these complexes interact with plane-polarized light.

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Related Practice

Textbook Question

Write the formula for each of the following compounds.

(a) Diamminesilver(I) nitrate

(b) Potassium diaquadioxalatocobaltate(III)

Textbook Question

Write the formula for each of the following compounds.

(d) Diamminebis(ethylenediamine)chromium(III) chloride

Textbook Question

Which of the following complexes are chiral?

(a) Pt(en)Cl₂

(b) cis-[Co(NH₃)₄Br₂]+

(d) [Cr(C₂O₄)₃]^3-

Textbook Question

Tris(2-aminoethyl)amine, abbreviated tren, is the tetradentate ligand N(CH2CH2NH2)3. Using to represent each of the three NCH2CH2NH2 segments of the ligand, sketch all possible isomers of the octahedral complex [Co(tren)BrCl]+.

Textbook Question

Consider the octahedral complex [Co(en)(dien)Cl]2+, where dien = H2NCH2CH2NHCH2CH2NH2, which can be abbreivated

(a) The dien (diethylenetriamine) ligand is a tridentate ligand. Explain what is meant by 'tridentate' and why dien can act as a tridentate ligand.

(b) Draw all possible stereoisomers of [Co(en)(dien)Cl]2+ (dien is a flexible ligand). Which stereoisomers are chiral, and which are achiral?

Textbook Question

The reaction of the octahedral complex Co(NH3)3(NO2)3 with HCl yields a complex [Co(NH3)3(H2O)Cl2]+ in which the two chloride ligands are trans to one another.

(a) Draw the two possible stereoisomers of the starting material [Co(NH3)3(NO2)3]. (All three NO2- ligands are bonded to Co through the N atom.)

(b) Assuming that the NH3 groups remain in place, which of the two starting isomers could give rise to the observed product?