[EDIT]Try this:
<?php
$args = array(
'posts_per_page' => '-1',
'post_type' => 'inversion',
'category_name' => '',
'order' => 'DESC',
'orderby' => 'date',
);
$the_query = new WP_Query( $args );
?>
<?php if ( $the_query->have_posts() ) : ?>
<div class="vc_row">
<?php
$float_class = '';
while ( $the_query->have_posts() ) :
$the_query->the_post();
if ( $the_query->current_post &&
$the_query->current_post % 2 === 0 ) {
$float_class = $float_class ? '' : 'vc_pull-right';
}
$imagen = get_the_post_thumbnail_url( get_the_ID(), 'full' );
?>
<div class="vc_col-sm-6">
<div class="vc_row vc_row-fluid">
<div class="vc_col-sm-6 cont-der <?php echo $float_class; ?>">
<a class="click-info">Más Información</a>
<div class="img-dentro kenburns-top" style="background:url('<?php echo esc_url( $imagen ); ?>') no-repeat; background-size:cover;">
</div>
</div>
<div class="vc_col-sm-6 cont-izq">
<h3><?php the_title(); ?></h3>
</div>
</div>
</div>
<?php endwhile; // end have_posts() loop ?>
</div><!-- .vc_row -->
<?php endif; // end have_posts() check ?>
<?php wp_reset_query(); ?>