Synthesis, Structure, and Magnetic Properties of Amine-Templated Transition-Metal Phosphites

Transition-metal phosphites of cobalt and vanadium, [C4N2H12][Co(HPO3)(2)] (I), [C4N2H14][Co(HPO3)(2)] (II), [Co[C4H8N12)(H2PO3)(2)] (III),[C4N2H14][(VF)-F-III(HPO3)(2)]center dot H2O (IV), and[C3N2H5](2)[V-4(III)(H2O)(3)(HPO3)(4)(HPO4)(3)] (V), have been synthesized and characterized. Organophosphorus esters were employed to stabilize cobalt in tetrahedral coordination and also to prepare the low-dimensional structures, which are otherwise difficult to synthesize. The structures have one- (I, II, IV), two- (III) and three-dimensionally (V) extended networks built up by the linking of metal polyhedra and phosphite units. Another vanadyl phosphite, [C2N2H10][((VO)-O-IV)(3)(H2O) (HPO3)(4)]center dot H2O,([15]) was also prepared and investigated extensively by ESR, magnetic susceptibility, and other studies. All the compounds in the present study exhibit antiferromagnetic interactions. Well-established magnetic models have been used to fit the experimental data. The compounds havealso been characterized in detail by using UV/Vis spectroscopic studies.

Medieval pulse of great earthquakes in the central Himalaya: Viewing past activities on the frontal thrust

The Himalaya has experienced three great earthquakes during the last century1934 Nepal-Bihar, 1950 Upper Assam, and arguably the 1905 Kangra. Focus here is on the central Himalayan segment between the 1905 and the 1934 ruptures, where previous studies have identified a great earthquake between thirteenth and sixteenth centuries. Historical data suggest damaging earthquakes in A.D. 1255, 1344, 1505, 1803, and 1833, although their sources and magnitudes remain debated. We present new evidence for a great earthquake from a trench across the base of a 13m high scarp near Ramnagar at the Himalayan Frontal Thrust. The section exposed four south verging fault strands and a backthrust offsetting a broad spectrum of lithounits, including colluvial deposits. Age data suggest that the last great earthquake in the central Himalaya most likely occurred between A.D. 1259 and 1433. While evidence for this rupture is unmistakable, the stratigraphic clues imply an earlier event, which can most tentatively be placed between A.D. 1050 and 1250. The postulated existence of this earlier event, however, requires further validation. If the two-earthquake scenario is realistic, then the successive ruptures may have occurred in close intervals and were sourced on adjacent segments that overlapped at the trench site. Rupture(s) identified in the trench closely correlate with two damaging earthquakes of 1255 and 1344 reported from Nepal. The present study suggests that the frontal thrust in central Himalaya may have remained seismically inactive during the last similar to 700years. Considering this long elapsed time, a great earthquake may be due in the region.

Microhyla laterite sp nov., A New Species of Microhyla Tschudi, 1838 (Amphibia: Anura: Microhylidae) from a Laterite Rock Formation in South West India

In recent times, several new species of amphibians have been described from India. Many of these discoveries are from biodiversity hotspots or from within protected areas. We undertook amphibian surveys in human dominated landscapes outside of protected areas in south western region of India between years 2013-2015. We encountered a new species of Microhyla which is described here as Microhyla laterite sp. nov. It was delimited using molecular, morphometric and bioacoustics comparisons. Microhyla laterite sp. nov. appears to be restricted to areas of the West coast of India dominated by laterite rock formations. The laterite rock formations date as far back as the Cretaceous-Tertiary boundary and are considered to be wastelands in-spite of their intriguing geological history. We identify knowledge gaps in our understanding of the genus Microhyla from the Indian subcontinent and suggest ways to bridge them.