Mercury atom

Figure 29.6 The structure of [Hg(>j -QH4PPh3)l2]2 showing the essentially tetrahedral coordination of the mercury atoms and of the carbon atoms attached to them.

Hg22+ is a polyatomic cation there is a covalent bond between the mercury atoms. 

In cinnabar, HgS, the sulfur atom has a normal-valence structure, in which it forms two bonds with mercury atoms. The Hg—S—Hg bond angle is 105°. The mercury atom may be described as forming two oppositely directed bonds with use of two sp hybrid bond orbitals the value of the S—Hg—S angle is 172°. The bond length, 2.36 A, leads,... 

Mercury atoms from the gas plume stick to the gold metal, causing an increase in mass. Thus, the increase in mass of the piece of gold equals the mass of Hg in the plume sample. 

C15-0071. The light-emitting decay of excited mercury atoms is first order, with a rate constant of... 

The reaction between Hg(II) and olefins has been examined from several angles and work prior to 1950 has been summarised by Chatt . Several types of complex and product are formed, depending on the olefin, which involve no change in the oxidation state of the mercury atom. Propenyl ethers have long been known to produce the corresponding glycol plus metallic mercury but no kinetics are available . 

The addition of the methylmercuriacetylcarbene to cis- and //ms-butene was found to be completely stereospecific, suggesting that this carbene has a singlet ground state (with the heavy mercury atom, relaxation to the ground state should be rapid). 

The mercury atom is four-coordinate, both nitrogen atoms being involved in intramolecular coordination. The reaction of (Cabc,N)SnMe2Br with Na afforded the bis(o-carboranylamino)distannane [(Cabc,N)SnMe2]2 53. The two tin atoms exhibit approximately trigonal-bipyramidal geometry. 

Ans. The actual formula implies that the two mercury atoms are covalently bonded together. 

A series of alkyl-substituted macrocycles featuring mercury atoms connected by c/-carborane units has been recently synthesized. Examples of such macrocycles include the hexamethyl derivative 58 and the hexadecamethyl derivative 59 whose alkyl-substituted carborane backbones impart improved solubility in hydrocarbon solvents.7 While 58 was synthesized from doso-9, 12-Mc -1 T-I.i -110I R and Hg(OAc)2, compound 59 was obtained as a... 

Polymercuration of (cyclobutadiene)cyclopentadienylcobalt complexes has also been reported. Upon reaction with Hg(OAc)2, complexes 88a-c afford a mixture of products containing one to five mercury atoms. Higher yields of the pentamercurials 89a-c were obtained when Hg(OCOCF3)2 was employed (Equation (34)). 

Longer Hg-7r interactions are observed in the /> ra-/-butylcalix[4]arene mercury complex 162. The mercury atom forms primary bonds with the two sulfur atoms and engages in weaker secondary interactions with two arene rings of the calixarene whose centroids sit at 3.07-3.11 A from the metal center.201... 

In an effort to characterize the species formed in vapors containing mercury and arenes upon irradiation with UV light, the formation of exciplexes between excited mercury atoms and arenes has been investigated theoretically. For benzene, these investigations suggest the formation of an exciplex involving the Hg atom in the state and an 772-bound molecule of benzene. This loose complex (3[Hg(772-arene)] Figure 9) with estimated Flg-C bonds of 2.36A... 

Reaction of 137 with [NBri4][SCN] leads to formation of the anionic complex [137-SCN]-, which adopts a multidecker structure with the anion sandwiched between successive molecules of 137 (Figure 13).212 The sulfur atoms of the SCN- ion in [ 137-SCN]- interacts unsymmetrically with the mercury atoms of the neighboring molecules of 137 forming four short Hg-S bonds that range from 3.06(1) to 3.36(1) A and two long bonds of 3.74(1) and 3.87(1) A. While the longer Hg-S bonds approach the limit for the involvement of dative interactions, the shorter ones are comparable to those observed in [163-SCN]. ... 

The reaction of the tetranuclear mercuracarborand 166 with 2 or 3 equiv. of KNO3/I8-C-6 in acetone affords two different nitrate complexes namely [166-(N03)2(H20)]2 and [166-(N03)2]2 (Figures 15 and 16). In both cases, the nitrate anions are ligated to the mercury centers by Hg-O interactions ranging from 2.60 to 3.08 A. In [166-(N03)2]2, the two anions coordinate with all four mercury atoms in a face-on trihapto fashion from either side of the plane.216... 

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