What are crystalline polymorphs?

What are crystalline polymorphs?

Polymorphism is the ability of a substance to crystallize into different crystalline forms. These crystalline forms are called polymorphs or crystalline modifications. Polymorphs have the same liquid or gaseous state but they behave differently in the solid state.

What is meant by isostructural?

Definition of isostructural : relating to or having a similar crystal structure in that the atoms correspond in position and function although there may not be close chemical relationship : isotypic —used of minerals and other crystalline substances calcite and sodium nitrate are isostructural — compare isomorphous.

What is isostructural example?

Compounds which are isoelectronic usually have similar chemical structures. For example, methane, CH4, and the ammonium ion, NH4+, are isoelectric and are isostructural as both have a tetrahedral structure.

What are isostructural minerals?

We defined isostructural and isotypic minerals, and learnt that isostructural minerals are those that have the same structure but different chemical composition; and that isotypism is a feature said to occur between two or more minerals that have analogous or similar structures.

What is good solubility for a drug?

A drug is considered highly soluble when the highest dose strength is soluble in 250 mL or less of aqueous media over the pH range of 1 to 7.5.

Which polymorph is more stable?

Polymorph A is the thermodynamically stable one, but its absorption in humans is significantly lower than that of polymorph B [72], because Form B dissolves faster than Form A, and has much higher solubility [73].

How do you find isostructural elements?

Hint: To find the isostructural species among the given compounds, we must find the hybridisation of the central atom of each species and the arrangement of the bond pairs and lone pairs on the central atom. To do that, you must recall the VSEPR (Valence shell electron pair repulsion) theory.

Are NF3 and NH3 isostructural?

NH3 and NF3 are isostructural with one lone pair on N-atom, but dipole moment of NH3 is greater than that of NF3.

How do you find isostructural?

Which species is isostructural?

Isostructural species are those which have the same shape and hybridisation. Among the given species, identify the isostructural pairs.

Which drug is water soluble?

Drugs that dissolve in water (water-soluble drugs), such as the antihypertensive drug atenolol, tend to stay within the blood and the fluid that surrounds cells (interstitial space). Drugs that dissolve in fat (fat-soluble drugs), such as the antianxiety drug clorazepate, tend to concentrate in fatty tissues.