http://www.runyvmat.com/As the industry leader in phosphine ligands and catalysts for homogeneous catalysis, Solvay offers a range of phosphorus compounds used in a breadth of applications and markets. Our scalable phosphorus chemistry meets the unique requirements of reactions that are crucial to several manufacturing processes across markets and applications, including petrochemicals, life sciences, flavors and fragrances, agrochemicals, fine chemicals, and plastics and other polymers. And do you what is Phosphine Ligands? Phosphines are a three-valent phosphorus compound and act as a "soft" σ-donating ligand with an unshared electron pair. This gives solubilization and stabilization to organometallic complexes by forming complexes with various transition metal species including latter-period transition metals and others, and is also used for controlling the reactivity and selectivity of the transition metal promoted reactions. Electron density and bulkiness of phosphine ligands are greatly related to the reactivity of their forming metal complexes. Generally, the phosphine ligands with high electron density increase the reactivity of oxidative addition from a metal center, and their bulkiness improves the reductive elimination. For example, trialkylphosphines especially tert-butyl or cyclohexyl group substituted phosphines show the highest electron density while the electron density of triarylphosphines and phosphite are sequentially decreasing. On the other hand, as an index of the bulkiness of phosphine ligands, that of monodentate phosphine ligands shows the cone angle (θ) while bidentate phosphine ligands show the bite angle (ω). As the angle of the phosphine ligands is wider, their steric effect is greater and they are regarded as more bulky phosphine ligands. A monodentate phosphine ligand of tri(o-tolyl)phosphine, and bidentate phosphine ligands of 1,1'-bis(diphenylphosphino)ferrocene and Xantphos are known as representative bulky phosphine ligands. There are many different kinds of Phosphine Ligands, such as Chiral Phosphine Ligands, Chelated Phosphine Ligands, Biaryl Phosphine Ligand, Trisubstituted Phosphine Ligands and Other Phosphine Ligands. Homogeneous catalysis is an efficient alternative to its heterogeneous counterpart, and enables access to certain molecules that are not accessible through heterogeneous catalysis. Our high-performance phosphine ligands provide endless customization opportunities for catalytic processes. Phosphorus chemistry offers substantial diversity of structure, tunability and thermal stability, which leads to its use in many essential industries and an abundance of applications. A majority of Solvay's phosphorus technologies are available in liquid or solution form, which facilitates ease of handling and safe product stewardship. Solids are available if preferred. Produced via industry-recognized manufacturing processes, our phosphine ligands and catalysts can be manufactured at any scale. Solvay offers expertise and manufacturing wherewithal at any phase of the value chain, but specializes in developing ligand solutions from the initial R&D stage all the way to industrial-scale production and distribution. Except for Phosphine Ligands, there are also many other material Intermediate and Function Materials like Catalyst including Homogeneous Catalyst and Olefin Copolymerization Catalyst. posted an update 1년, 7개월전
http://www.cyrhinestones.com/If you pay more attention on the jewelry, bags or apparel, you will find rhinestones are everywhere! Rhinestones are shiny and eye-catching and they are great for adding sparkle to accessories. They look like diamonds but are not diamonds.
The definition of rhinestones is “An imitation diamond, used in cheap jewellery and to decorate clothes.” according to Oxford dictionary. Besides, according to Merriam Webster, America’s leading and most-trusted provider of language information, rhinestone is “imitation stone of high luster made of glass, paste, or gem quartz.”
We can tell from its definition that the word “rhinestone” can be used widely. From the high-grade Swarovski crystal to normal glass stones or inexpensive plastic stones like acrylic or resin material, they can all be called as rhinestones. There are many kinds of Rhinestones such as Hotfix Rhinestones, Glass Flatback Rhinestones, Flatback Rhinestones, Non Hotfix Rhinestones, Shaped Rhinestones, Non Hotfix Shaped Rhinestones, Hotfix Shaped Rhinestones, Nail Rhinestones, Small Rhinestones, Micro Rhinestones, etc.
Ways to Tell Rhinestones and Diamonds Apart
Here are some of the most reliable ways to distinguish between diamonds and rhinestones:
A distinctive characteristic of diamond is that due to its physical properties, it does not retain moisture on its surface for a long time. So, if you breathe on a real diamond, the fog created from your breath on the stone will dissipate very quickly, almost instantaneously. If you do the same test with a rhinestone, however, it will stay foggy for some time (usually 5-10 seconds).
Diamonds distort the light that passes through them, and this is why if you try to read printed text through a real diamond, the letters will look blurry. If you try to do the same with a rhinestone, the text will be more easily readable (close to how you would see it through glass). Keep in mind, however, that diamonds that are cut shallow and have parallel walls (e.g., emerald-cut or baguette-cut stones) may not distort text as visibly, making this test inconclusive.
Rhinestones Are Softer than Diamonds
Diamond is the hardest gemstone, and whatever imitation you are looking at, it is bound to be softer that the real thing. Because they are not as hard as diamonds, rhinestones are much easier to scratch, and over time, these scratches accumulate on their surface. Diamonds, on the other hand, are nearly impossible to scratch from everyday wear (they can chip if hit too hard, though). The relative softness of a cut rhinestone can also be seen in its facets, whose edges tend to be somewhat round for that reason. The edges of a diamond’s facets are sharper, and due to the hardness of the material, they do not wear out with time.
Using Diamond Testers
Diamond testers are devices that check the conductive properties of a material to test whether it is diamond. Although these tools can tell you if a stone is not a real diamond, they won’t show whether it is a rhinestone or something else.
Price as a Sign of Authenticity
Rhinestones are much cheaper than real diamonds of similar size, color, and clarity. Although the low price may indicate that you are not dealing with a genuine diamond, some sellers may try to sell you a rhinestone pretty expensively. Use price as a clue only in conjunction with other tests.