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Chromium compounds are compounds containing the element chromium (Cr). Chromium is a member of group 6 of the transition metals. The +3 and +6 states occur most commonly within chromium compounds, followed by +2; charges of +1, +4 and +5 for chromium are rare, but do nevertheless occasionally exist. [3] [4]
Chromium supplementation in general is subject to a certain amount of controversy as it is by no means clear that chromium is an essential element in human biology. [25] Nevertheless, chromium is an ingredient in total parenteral nutrition, along with other trace minerals. [26] It is also in nutritional products for preterm infants. [27]
Chromium is a chemical element; it has symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. [10] Chromium is valued for its high corrosion resistance and hardness.
Trivalent chromium, or chromium(III), is an essential trace mineral in the human diet. [3] In some nutritional supplements, chromium(III) occurs as chromium(III) picolinate (in which chromium is bound to picolinic acid) or chromium(III) nicotinate (in which chromium is bound to nicotinic acid). Nicotinic acid is also known as the B vitamin niacin.
Chromium(II) acetate hydrate, also known as chromous acetate, is the coordination compound with the formula Cr 2 (CH 3 CO 2) 4 (H 2 O) 2. This formula is commonly abbreviated Cr 2 (OAc) 4 (H 2 O) 2 . This red-coloured compound features a quadruple bond .
Chromium(III) nicotinate contains three nicotinic acid units per chromium ion; that is, it is the trinicotinate of chromium(III). The substance that is used in supplements and called "chromium polynicotinate" is said to be a mixture of the tri nicotinate and the di nicotinate, with the former dominating.
Chromium(III) nitrate describes several inorganic compounds consisting of chromium, nitrate and varying amounts of water. Most common is the dark violet hygroscopic solid. An anhydrous green form is also known. Chromium(III) nitrate compounds are of a limited commercial importance, finding some applications in the dyeing industry. [2]
For example, with the Wulff–Dötz reaction an alkyne, carbon monoxide, and a chromium carbene are combined to form a chromium half-sandwich complex [8] [9] and the phenol ligand can be isolated by mild CAN oxidation. CAN is used to cleave para-methoxybenzyl and 3,4-dimethoxybenzyl ethers, which are protecting groups for alcohols.